‘ Validate an e-mail address’ Example:’ MessageBox.Show(IsValidEmail(“[email protected]”)) ‘ True’ MessageBox.Show(IsValidEmail(“vb2themax.com”)) ‘ False’ MessageBox.Show(IsValidEmail(“mbellinaso@vb2themax”)) ‘ FalseFunction IsValidEmail(ByVal email As String) As Boolean Return System.Text.RegularExpressions.Regex.IsMatch(email, _ “^w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*$”)End Function

‘ Validate a US ZIP code’ Example:’ MessageBox.Show(IsValidUsZip(“12345”)) ‘ => True’ MessageBox.Show(IsValidUsZip(“12345-1234”)) ‘ => True’ MessageBox.Show(IsValidUsZip(“12345-12345”)) ‘ => FalseFunction IsValidUsZip(ByVal zip As String) As Boolean Return System.Text.RegularExpressions.Regex.IsMatch(zip, _ “^(d{5}-d{4})|(d{5})$”)End Function

‘ Validate a URL’ Example: MessageBox.Show(IsValidUrl(“http://www.vb2themax.com”))Function IsValidUrl(ByVal url As String) As Boolean Return System.Text.RegularExpressions.Regex.IsMatch(url, _ “(http|ftp|https)://([w-]+.)+(/[w- ./?%&=]*)?”)End Function

‘ Validate an IP address’ Example:’ MessageBox.Show(IsValidIP(“123.14.0.255”)) ‘ => True’ MessageBox.Show(IsValidIP(“256.14.0.255”)) ‘ => FalseFunction IsValidIP(ByVal ipAddress As String) As Boolean Return System.Text.RegularExpressions.Regex.IsMatch(ipAddress, _ “^(25[0-5]|2[0-4]d|[0-1]?d?d)(.(25[0-5]|2[0-4]d|[0-1]?d?d)){3}$”)End Function

‘ Validate a US Social Security Number’ Example:’ MessageBox.Show(IsValidUsSSN(“123-12-1234”)) ‘ True’ MessageBox.Show(IsValidUsSSN(“123-123-1234”)) ‘ FalseFunction IsValidUsSSN(ByVal ssn As String) As Boolean Return System.Text.RegularExpressions.Regex.IsMatch(ssn, _ “^d{3}-d{2}-d{4}$”)End Function

‘ Validate a US phone number’ Example:’ MessageBox.Show(IsValidUsPhoneNumber(“(123) 456-7890”)) ‘ True’ MessageBox.Show(IsValidUsPhoneNumber(“(123) 456-78901”)) ‘ FalseFunction IsValidUsPhoneNumber(ByVal phnNum As String) As Boolean Return System.Text.RegularExpressions.Regex.IsMatch(phnNum, _ “^(((d{3}) ?)|(d{3}-))?d{3}-d{4}$”)End Function

‘ Validate a system path’ Example:’ MessageBox.Show(IsValidPath(“C:TestMemo.txt”)) ‘ => True’ MessageBox.Show(IsValidPath(“\RemotePCTestMemo.txt”)) ‘ => True’ MessageBox.Show(IsValidPath(“C:TestMem|o.txt”)) ‘ => FalseFunction IsValidPath(ByVal path As String) As Boolean Try Dim f As New System.IO.FileInfo(path)

‘ this code assumes that you have used this Imports statement’ Imports Microsoft.Win32Function IsExcelInstalled() As Boolean ‘ Define the RegistryKey objects for the registry hives. Dim regClasses As RegistryKey =

‘ Extract the name of the SoapException’s (the type of exception thrown by a ‘ web service) “inner” exception.” Example:’ Try’ ‘ this call throws an exception’ Dim service As

‘ Execute a batch of OleDb commands.’ Parameters:’ – The list of statements separated by ; chars. Use the ? char as a ‘ placeholder for a parameter.’ – The

‘ Search the specified string, with the case-sensitive mode or not’ Returns the index of the first occurrence found, or -1 if not foundPublic Function SearchString(ByVal source As String, ByVal

‘ Reverse the input string, without using the StrRever function in the VB6 ‘ compatibility assemblyFunction ReverseString(ByVal source As String) As String Dim chars() As Char = source.ToCharArray() Array.Reverse(chars) Return

‘ this code assumes that you have used this Imports statement’ Imports Microsoft.Win32Function IsWordInstalled() As Boolean ‘ Define the RegistryKey objects for the registry hives. Dim regClasses As RegistryKey =

‘ Count the number of string occurrencesPublic Function CountOccurrences(ByVal source As String, ByVal search As String, _ Optional ByVal ignoreCase As Boolean = False) As Integer Dim options As System.Text.RegularExpressions.RegexOptions

‘ Return the number of checked nodes in the specified treePublic Function CountCheckedNodes(ByVal rootNode As TreeNode) As Integer Dim count As Integer = 0 ‘ count the root node, if

If you want your program to be easily translated into a different language, consider making every displayed text a resource in a dll. Every language will have its own .dll

You will never have to check the form tag for local page postbacks.This nipped me once.

What happens if your visitors have it disabled?Include the following code to: Let them know that JavaScript is disabled. Tell them how to enable it in their browser. To view

If you have used a native method through a Java interface, then you might already know that a header file is generated from the Java class that contains the native

To program a case-sensitive comparison of a user-typed password on a case-insensitive SQL Server 7.0 instance, assume that the value of the password stored in your table is BamBi2000 (notice

A normal practice in implementing a search is to use the “like” operator. As long as you are searching for your keyword in only one column, there will be no