function RestrictSpaceSpecial(e)
{
var k;
document.all ? k =
e.keyCode : k = e.which;
return ((k > 64 && k < 91) || (k > 96 && k < 123) || k == 8 || k == 32 ||
(k >= 48 && k <= 57));
}
Now access the JavaScript function
on keypress event of textbox as shown below:
<asp:TextBox ID="TextBox2" runat="server" onkeypress="RestrictSpaceSpecial();" />