If you have a need to validate a user input or string to ensure that only a valid email is entered , then you can use Regular Expressions or REGEX to handle that easily.
REGEX expressions appear to be quite complicated but once you have a valid syntax then it is simply a matter of using the proper syntax of REGEX in the following function and you should also be able to use the same function block to handle other types of inputs as well. eg. Numeric
The following function will validate your input against a valid email address.
At the top of your module or form add the following line of code
Add the following function in your form
Function Validate_Email(ByVal value As String) As Boolean
Dim bok As Boolean = False
Dim s As String
s = LCase(value)
Dim myMatch As Match = System.Text.RegularExpressions.Regex.Match(s, “^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$”)
If myMatch.Success Then
bok = True
bok = False
How to use the function
Dim bok as boolean
bok = Validate_Email( YourInputTextHere)
If the user input is a valid email then bok will be true else false.