เกี่ยวกับ code ครับ ช่วยหน่อย คำสั่งเกี่ยวกับ ดักค่า เบอร์โทรศัพท์

<?
$as="0814578569";
if('9' <= strlen($as) and strlen($as)<='10'){
echo "a";
}else{
	echo "b";
}
?>

<script type="text/javascript">
function validate(frm){
	
	if( frm.ENickName.value=='') {
		alert('Please enter Nickname!');
		return false;	
	}else if( frm.EFirstName.value == '' ) {
		alert('Please enter English First Name');
		return false;
	}else if( frm.ELastName.value == '' ) {
		alert('Please enter English Last Name');
		return false;
	}else if( frm.TNickName.value == '' ) {
		alert('Please enter Thai Nickname');
		return false;
	}else if( frm.TFirstName.value == '' ) {
		alert('Please enter Thai First Name');
		return false;
	}else if( frm.TLastName.value == '' ) {
		alert('Please enter Thai Last Name');
		return false;
	}else if( frm.Address.value == '' ) {
        alert('Please enter Address');
        return false;
    }else if( frm.Email.value == ''){
        alert('Please enter Email');
        return false;
    }else if(!checkEmail(frm.Email.value)){
        alert('Not a valid e-mail address');
        return false;

            function checkEmail(inputvalue){  
                var pattern=/^([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;
                if(pattern.test(inputvalue)){       
                    return true;
                }else{ 
                    return false;
                }
/*               
                else if( frm.IT.checked == false ) {
                    alert('pls check!');
                    return false;  
                }           
*/
        }
    }
  
    return true;
}
</script>

		if('9' <= strlen($_POST["phone"]) and strlen($_POST["phone"])<='10')
	{}else
	{
		echo "<script> alert('กรุณาเบอร์โทรศัพท์ให้ถูกต้อง!')</script>";
		print "<meta http-equiv=refresh content=0;URL=register.php>";
		exit();
	}