ช่วยดูโค้ดให้หน่อยค่ะ ทำไงให้มัน alert ออกมาเป็นค่าที่โพส

<script>
function checkf() {
var arr = document.formsend1.number_phone.value.split(',')
	n=0;
	l = arr.length;
	while (n < l)
		
	if (arr[n].length < 10){
			var phone = document.getElementById("tel").value;
			alert("phone  " + arr[n].length + "  needed 10 digit ! \r\n "+"phone number : "+phone);
			return false;
		}
			if (arr[n].length >= 11){
			alert("phone" + arr[n].length + "over 10 digit !");
			return false;
		}
		n++;
	}
</script><form name='formsend1' method='post' action='separate_48.php'>
<textarea name='number_phone' id="tel" cols='30' rows='5' wrap='VIRTUAL' onblur="checkNumbers(this);" onfocus="setcount();" onchange="setcount();" onkeypress="setcount();" class='boxi'></textarea></form><br /><br />
<input type='button' name='send' value='Sent' onfocus="checkWordBad($word)" onClick='checkf();' class='buto1'>