입력값 숫자체크

<script language="javascript">
function checkNumber(){
    var objEv = event.srcElement;
    var numPattern = /([^0-9])/;
    numPattern = objEv.value.match(numPattern);
    if(numPattern != null){
        alert("숫자만 입력해 주세요!");
        objEv.value="";
        objEv.focus();
        return false;
    }
}
 
</script>

<form>
<input type="text" name="tel1" onchange="checkNumber()" size="3"> -  <input type="text" name="tel2" onchange="checkNumber()" size="4"> -  <input type="text" name="tel3" onchange="checkNumber()" size="4">
</form>