I am using a acript to control the input field of my page where it can enters numbers only in telephone field. Can anyone help me on how to modify the code to allow a symbol '+' ?
<script>
function zz(txt)
{
var txt1 = txt.value.replace(/[A-z]/g, "");
document.getElementById('aa').value = txt1;
}
</script>
<input type="text" id="aa">