You can use following JS Function :
function DisableSplChars(e)
{
var keynum
var keychar
var numcheck
if (window.event)
{
keynum = e.keyCode
}
else if (e.which)
{
keynum = e.which
}
keychar = String.fromCharCode(keynum)
if (keychar == "!" || keychar == "@" || keychar == "#"
|| keychar == "$" || keychar == "%" || keychar == "^" || keychar == "&"
|| keychar == "*" || keychar == "(" || keychar == ")"
|| keychar == "<" || keychar == ">")
{
return false;
}
else
{
return true;
}
}
And on Textbox you can call this javascript function
onkeypress="javascript:return DisableSplChars(event);"