判断一段字符中是否含有电话号码的方法_js

<script LANGUAGE=”JavaScript“>
<!–
function checkNum(str){return !//d{6}/.test(str)}
function check()
{
if (document.form.tell.value==””){
  alert(“入a！”);
  document.form.tell.focus();
  return false;
}
else{
  var Letters = “0123456789()+-“;
  for (i=0; i< document.form.tell.value.length; i++){
     var CheckChar = document.form.tell.value.charAt(i);
     if (Letters.indexOf(CheckChar) == -1){
       alert(“a格式不正_！”);
       document.form.tell.focus();
       return false;
      }
    }
  }
}
//–>
</script>

<form method=”POST” name=form action=”” >
<p align=”center”>
   请输入电话号码：<input type=”text” name=”tell” size=”20″>
<input type=”submit” value=”提交” name=”B1″></p>
</form>