Software Applications Programming Errors and solutions.

What is Digital signatures   A major benefit of public key cryptography is that it provides a method for employing digital signatures. Digital signatures let the recipient of information verify the authenticity of the information’s origin, and also verify that the information was not altered while in transit. Thus, public key digital signatures provide authentication and data integrity. These features are every bit as fundamental to cryptography as privacy, if not more.  A digital signature serves the same purpose as a seal on a document, or a hand-written signature. However, because of the way it is created, it is superior to a seal or signature in an important way. A digital signature not only attests to the identity of the signer, but it also shows that the contents of the information signed has not been modified.  A physical seal or handwritten signature cannot do that. However, like a physical seal that can be created by anyone with possession of the sig...

TYPES OF TRANSISTOR There are two types of standard transistors: NPN PNP with different circuit symbols. The letters refer to the layers of semiconductor material used to make the transistor. Most transistors used today are NPN because this is the easiest type to make from silicon. If we are new to electronics it is best to start by learning how to use NPN transistors. The leads are labeled base (B), collector (C) and emitter (E). These terms refer to the internal operation of a transistor but they are not much help in understanding how a transistor is used, so just treat them as labels A Darlington Pair is two transistors connected together to give a very high current gain. In addition to standard (bipolar junction) transistors, there are field-effect transistors, which are usually referred to as FET.

 What Spread Spectrum Does? The use of these special pseudo noise codes in spread spectrum (SS) communications makes signals appear wide band and noise-like. It is this very characteristic that makes SS signals possess the quality of Low Probability of Intercept. SS signals are hard to detect on narrow band equipment because the signal’s energy is spread over a bandwidth of maybe 100 times the information bandwidth. A spread spectrum system is one in which the transmitted signal is spread over a wide frequency band, much wider, in fact, than the minimum bandwidth required to transmit the information being sent. Spread spectrum communications cannot be said to be an efficient means of utilizing bandwidth. However, it does come into its own when combined with existing systems occupying the frequency. The spread spectrum signal being “spread” over a large bandwidth can coexist with narrow band signals only adding a slight increase in the noise floor that the narrow band receivers ...

Benefits of ERP Better business practices with re engineering of process as this becomes a prerequisite to ERP. Accurate and timely information. Eliminate duplication in work. Better customer satisfaction. Improve operational Efficiency. Reduce avoidable costs and losses. Better inventory management. Facilitates knowledge management. Better employee satisfaction. Better planning and preparedness. Example of ERP- Microsoft dynamics axapta, Navision,CRM,SAP, Oracle,Tally ,Baan,LN etc.

CHARACTERISTICS OF COMPUTER   1. Speed: Computer can do calculations at the super fast speed without any mistake. A modern computer can execute about thirty million instructions in one second. 2. Accuracy: Computer never gives wrong results nature. In fact the most computer errors are caused due to wrong input of data and instructions. 3. Diligence: It is away from basic human nature. It never bored or tired and it can work for long times without creating any error. 4. Storage Capacity: It can store a large amount of information in a very small space. We can display the stored information whenever desired. 5. Versatility: It is one of the most wonderful thing about computer. It can do various jobs at one time. 6. Automatic: They are capable of automatically performing repetitive or long process without making any errors. 7. Power Of Remembering: It can store or recall any information as well as when we required. Computer does not make any guess or forget.

 Message transfer agent (MTA) The MTA is software running on a dedicated workstation or computer and is part of the email system’s backbone. Each MTA communicates with one or more UA’s and other MTAs. Its basic function is to accept mail from a UA or another MTA, examine it, and route it. For example, when it receives mail from a UA it verifies the format of the mail. If it is not correct it informs the UA an error has occurred so the sender can be notified. If it is correct there are two possibilities.  First, the recipient is reachable via another UA to which the MTA is connected. Example is user A sending mail to user B connected to same MTA. In this case the MTA gives the mail to the appropriate UA for delivery. Second, the UA that will deliver the mail is connected to another MTA. Here user A may have sent mail to user C connected to some other MTA. In this case the mail must be routed to another MTA. Collectively the MTAs execute a routing strategy that sends the m...

Introduction of  proxy server A proxy server is a kind of gateway that speaks HTTP to the browser but FTP, Gopher, or some other protocol to the server. It accepts HTTP requests and translates them into, say, FTP requests, so the browser does not have to understand any protocol except HTTP. The proxy server can be a program running on the same machine as the browser, but it can also be on a free-standing machine somewhere in the network serving many browsers. Often users can configure their browsers with proxies for protocols that the browsers do not speak. In this way, the range of information sources to which the browser has access is increased. In addition to acting as a go-between for unknown protocols, proxy servers have a number of other important functions, such as caching. A caching proxy server collects and keeps all the pages that pass through it. When a user asks for a page, the proxy server checks to see if it has the page. If so, it can check to see if the page ...

Coloring in particular cells using data grid foreach (DataGridViewRow dataGridViewRow in dataGridView1.Rows) { DataGridViewCellStyle dataGridViewCellStyle = new DataGridViewCellStyle(); dataGridViewCellStyle.ForeColor = Color.Red; if (dataGridViewRow.Cells[2].Value != null) { if (dataGridViewRow.Cells[2].Value.ToString().Trim().Equals("M", StringComparison.CurrentCultureIgnoreCase)) { dataGridViewRow.DefaultCellStyle = dataGridViewCellStyle; } } }

code to disable ctrl+alt+del key using .net Use this code in .net for disable A-C-D Dim regkey As Microsoft.Win32.RegistryKey Dim subkey As String subkey = "Software\Microsoft\Windows\CurrentVersion\Policies\System" regkey = My.Computer.Registry.CurrentUser.CreateSubKey(subkey, Microsoft.Win32.RegistryKeyPermissionCheck.ReadWriteSubTree) regkey.SetValue("DisableTaskMgr", 0) To Again enable A-C-D use this subkey = "Software\Microsoft\Windows\CurrentVersion\Policies\System" regkey = My.Computer.Registry.CurrentUser.CreateSubKey(subkey, Microsoft.Win32.RegistryKeyPermissionCheck.ReadWriteSubTree) regkey.SetValue("DisableTaskMgr", 1) after this Restart PC and use this Function Public Sub RestartComputer() Dim t As Single Dim objWMIService, objComputer As Object 'Now get some privileges objWMIService = GetObject("Winmgmts:{impersonationLevel=impersonate,(Debug,Shutdown)}") For Each objC...

MCTS 70-562 exam code of ASP.NET for 3.5 framewok 1) MCTS 70-536 is the exam based on core framework,you can choose VB or C# any preferred language of your choice. 2) you can take the gap in between exams 3) you can download sample exam questions from net, like ucertify.com , etc. Certification books is also there by ms publications & there is lot of online material for study. 4) you can purchase online voucher from microsoft and give the exam at any prometric center in your city or you can contact your local prometric center nd ask them to purchase a voucher.Voucher cost 50$ (Rs2500/- appx.),

How to use interfaces in  .Net An interfaces contains only the signatures of methods.The implementation of the methods is done in the class that implements the interface. SYNTAX: interface interface_name { void method1() void method2() } By default all the methods in interfaces are fully "public abstract" Example: ======= interface inter1 { void getdata(); void putdata(); } class sample1:inter1 { int eno; string ename; { public void getdata() { console.writeline("enter employee number"); eno=int.parse(console.readline()); console.writeline("enter employee name"); ename=console.readline(); } public void putdata() { console.writeline("employee number:"+eno); console.writeline("employee name:"+ename); } } class class1 { static void main () { sample1 obj=new sample1(); obj.getdata(); console,.writeline(); obj.putdata(); } ...