How to validate input field for phone number upto 10 digit and only number?

Question

This is my input field for phone and i want to validate phone number 1) Only number are allowed 2) Only Upto 10 Digit number are allowed

<input class="form-control" type="text" name="phone" onkeypress='validate(event)'>

and in script file i tried this for only number are allowed,no alphabet are allowed

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();
        }

    }

But i need validation for both only number are allowed and upto 10 digit