How to Validate Phone number Jquery Number

I want to validate this input for phone.Up to 10 digit only and no text allowed only number digit

<input type="text" name="phone" onkeypress='validate(event)'>

Although no text allowed worked but how to validate upto maximun 10 digit

<script>
function validate(evt) {
    var theEvent = evt || window.event;
    var key = theEvent.keyCode || theEvent.which;
    key = String.fromCharCode( key );
    var regex = /[0-9]|\./;
    if( !regex.test(key) ) {
        if(!regex.test(key) >=10 && !regex.test(key)<=10){
            theEvent.returnValue = false;
            if(theEvent.preventDefault) theEvent.preventDefault();
        }

    }
}
</script>