HTML text input allow only numeric input

Use the following code to allow only numeric input

<input type=’text’ onkeypress=’validate(event)’ />

<script>

function validate(evt) {
var theEvent = evt || window.event;

// Handle paste
if (theEvent.type === ‘paste’) {
key = event.clipboardData.getData(‘text/plain’);
} else {
// Handle key press
var key = theEvent.keyCode || theEvent.which;
key = String.fromCharCode(key);
}
var regex = /[0-9]|\./;
if( !regex.test(key) ) {
theEvent.returnValue = false;
if(theEvent.preventDefault) theEvent.preventDefault();
}
}

</script>