Javascript prevent special char
onkeypress
HTML
<form id="frm" runat="server">
<input type="text" name="name" onkeypress="return blockSpecialChar(event)"/></form>
JavaScript
function blockSpecialChar(e) {
var k = e.keyCode;
return ((k > 64 && k < 91) || (k > 96 && k < 123) || k == 8 || (k >= 48 && k <= 57));
}