DisAllow single quotes in textbox field

Hello,
 I have a asp.net form and bunch of textboxes in there. I want to disallow the ' single quote character in the textboxes. When I type in the following I get an error for every character type

ValidationExpression = " ^'  "(ignore the spaces here)
Example even if i type testing it gives me the error. 

Any suggestions please. 
 
 Thanks.
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