javascript驗證

Question

我有兩個單選按鈕。每個人都有一個關聯的文本框。如果我點擊一個單選按鈕，然後提交一個警告框，如果相關的文本框是空的，應該顯示。我怎樣才能做到這一點？

<form action="#" name="form1" id="form1" method="post" onsubmit="return check_workorder()"> 
    <input type="radio" name="click" id="click1" checked="checked" value="date"/> 
      <strong>Start Date&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
       <input type="text" id="my_date_field" name="my_date_field" class="datepicker" style="width:80px;"/> 
       </strong> 
      <script language="JavaScript" type="text/javascript"> 
      new Control.DatePicker('my_date_field', { icon: 'images/calendar.png' }); 
      </script> 
      </br><br /> 
      <input type="radio" name="click" id="click2" value="order" /> 
      <strong>Work order no 
      <input type="text" name="workno" id="workno" style="width:100px;"/> 
      </strong><span class="submit"> 
      <input type="submit" name="submit" value="submit" onclick="return check_workorder()"/> 

的JavaScript是

function check_workorder() { 
    if (document.forms.form1.elements.click.value == "date") { 
     var dat = (form1.my_date_field.value); 
     if (dat == "") { 
      alert("please select date"); 
      return false; 
     } 
    } else if (document.forms.form1.elements.click.value == "order") { 
     var wor = (form1.workno.value); 
     if (wor == "") { 
      alert("please enter work order no"); 
      return false; 
     } 
    } 
} 

Answer 1

if (document.forms.form1.elements.click.value == "date") { 
    if (document.forms.form1.elements.click.checked) { 
    //the radio button is checked 
    } 
}