How can I make sure only A-Z,a-z,0-9, _ , and . are used in a txtbox?

[trend]

How can I make sure only A-Z,a-z,0-9, _ , and . are used in a txtbox?

 

Basically, I am trying to prevent against sql injections....

 

 

I have seen:

Me.ValidationExpression = "^([a-zA-Z0-9_\-])([a-zA-Z0-9_\-\.]*)@(\[((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\.){3}|((([a-zA-Z0-9\-]+)\.)+))([a-zA-Z]{2,}|(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\])$"

 

and I am guessing I want something like:

 

([a-zA-Z0-9_\-]) then plus _ and . but I am unsure how to implement this.

 

Any help would be great!

 

 

thanks

Lee

[PlausiblyDamp]

If you use parameterised queries then you will not need to filter the input to prevent against injections.