Validate Special Characters in Memo

function specialchar(Detail)

 

            {

 

                var iChars = "!`@#$%^&*()+=-[]\\\';,./{}|\":<>?~_";

                var data = document.getElementById(Detail).value;

 

                for (var i = 0; i < data.length; i++)

                {

                    if (iChars.indexOf(data.charAt(i)) != -1)

                    {

 

                    alert ("string has special characters.");

                    document.getElementById(Detail).value = "";

                    return false;

                    }

                }

 

            }
But when i call this function in Button event OnClick=SpecialChar("Details")&Language=JScript

getting error as Engine Exception:Failed to refresh form when i click on Button.
what wrong in my script is any other method to do.