isNumeric.js

<script>
// This function will allow 0123456789, left, right, and backspace on a textbox
// Use onkeypress="return isNumericKeyPress(event.keyCode);" to trigger
function isNumericKeyPress(keyCode)
{
	return (keyCode >= 48 && keyCode <= 57 || keyCode === 8);
}

// This function will clear non-numeric values on a textbox when pasted
// Use onpaste="isNumericPaste(this);" to trigger
function isNumericPaste(tb)
{
	setTimeout(function() { void(tb.value = tb.value.replace(/\D/g, '')); }, 1);
}
</script>