How to check for character?

Hello, i need to check the character whcich the user input. For eg: I got email add, then need them to enter the full address of the email, then i need to check where the @ sign exists.
So how do i check? Can pls give mi some codes, i need this urgently. Thanks all the kind souls out there, hav a nice day...

you mean this? ...

VB Code:

[COLOR=blue]If Not[/COLOR] TextBox1.Text.IndexOf("@") = -1 [COLOR=blue]Then[/color]
            [COLOR=blue]Dim[/color] x [COLOR=blue]As Integer[/color] = TextBox1.Text.IndexOf("@")
            MessageBox.Show("the textbox contains the @ sign at char posistion : " & x)
        [COLOR=blue]End If[/color]

Sorrie, no, i mean is i need to check whether the user enter email add in the text box got the @ sign anot. If not, then need to prompt them error, if got, then save into the database.

the above code does check to see if there's an @ symbol , all you need is to make it suit your needs , eg:

VB Code:

[color=blue]If Not[/color] TextBox1.Text.IndexOf("@") = -1 [color=blue]Then[/color] [color=green]'/// if the string contains the @ symbol[/color]
            [color=green]'/// carry out your code for the string because it contains an email address.[/color]
        [color=blue]Else[/color] [color=green]'/// if it doesn't contain the @ symbol...[/color]
            MessageBox.Show("you did not type a valid email address, please try again!")
        [color=blue]End If[/color]

Oh, it works. Thanks a lot.
So how about checking for like not more than 1 @ sign?
Then how to check e email should be .com/.gov/.edu... etc behind?

like this then ...

VB Code:

[COLOR=BLUE]If[/COLOR] [COLOR=BLUE]Not[/COLOR] TextBox1.Text.IndexOf("@") = -1 [COLOR=BLUE]Then
[/COLOR]            [COLOR=BLUE]Dim[/COLOR] x [COLOR=BLUE]As[/COLOR] [COLOR=BLUE]Integer[/COLOR] = [color=black]UBound[/color](TextBox1.Text.[color=black]Split[/color]("@"c))
            [COLOR=BLUE]If[/COLOR] x = 1 [COLOR=BLUE]Then
[/COLOR]                [COLOR=BLUE]If[/COLOR] TextBox1.Text.EndsWith(".com".ToLower) [COLOR=BLUE]Or[/COLOR] TextBox1.Text.EndsWith(".net".ToLower) [COLOR=BLUE]Or[/COLOR] TextBox1.Text.EndsWith(".gov".ToLower) [COLOR=BLUE]Then
[/COLOR]                    [COLOR=GREEN]'/// it ends with .com or .net or .gov ( etc... depending what you want to look for at the end of the address )
[/COLOR]                    [COLOR=GREEN]'/// do your stuff here because it's a valid address...
[/COLOR]                [COLOR=BLUE]End[/COLOR] [COLOR=BLUE]If
[/COLOR]            [COLOR=BLUE]Else
[/COLOR]                [COLOR=GREEN]'/// it's got more than 1 @ symbol.
[/COLOR]                MessageBox.Show("to many @ symbols in the address!")
            [COLOR=BLUE]End[/COLOR] [COLOR=BLUE]If
[/COLOR]        [COLOR=BLUE]Else
[/COLOR]            MessageBox.Show("Oops that's not a valid email address!")
        [COLOR=BLUE]End[/COLOR] [COLOR=BLUE]If[/COLOR]