<script language="JavaScript" type="text/JavaScript">
function go(){
if (form1.test.selected==1){ 
alert ("1")
}
</script>

解决方案 »

  1.   

    <script language="JavaScript" type="text/JavaScript">
    function go(){
    //if (form1.test.value==1){ 
    alert (form1.test.options[0].value)
    //}
    </script>
    <BODY>
    <form name="form1" method="post" action="test.php">
    <SELECT NAME="test" onchange="go()">
    <option value="1">alfred</option>
        <option value="2">nomad</option>
    </SELECT>
    </form>
      

  2.   

    <script language="JavaScript" type="text/JavaScript">
    function go(){
      if (form1.test.value==2){ 
      alert (form1.test.value)
      }
    }
    </script>
    <BODY>
    <form name="form1" method="post" action="test.php">
    <SELECT NAME="test" onchange="go()">
    <option value="1">1</option>
        <option value="2">2</option>
    </SELECT>
    </form>
    </body>
      

  3.   

    try this:<script language="JavaScript" type="text/JavaScript">
    function go(){
      if (form1.test.value==1){ 
      form1.d2.disabled=false
      form1.d3.disabled=true
      }
      else if(form1.test.value==2)
      {
           form1.d3.disabled=false
           form1.d2.disabled=true
      }
    }
    </script>
    <BODY>
    <form name="form1" method="post" action="test.php">
    <SELECT NAME="test" onchange="go()">
    <option selected>please select</option>
    <option value="1">1</option>
        <option value="2">2</option>
    </SELECT>&nbsp; 
    <select size="1" name="d2">
        <option>231</option>
        <option>321312</option>
    </select>
        <select size="1" name="d3">
        <option>312321321</option>
        <option>312312312</option>
        <option>asddasd</option>
    </select></form>
    </body>
      

  4.   

    form1.test.value 错误! ==》
    form1.test.options[form1.test.selectedIndex].text