設置一個下拉從另一個

Question

選擇後，我有一對夫婦選擇元素：

<select name="empID" onchange='setSupervisor(this);'> 
    <option value="111" sid="222">Eric Employee</option> 
    ... 
</select> 

<select name="supervisorID"> 
    <option value="333">Susie Supervisor</option> 
    <option value="222">Stan Supervisor</option> 
</select> 

而且javascript功能：

function setSupervisor(sender) 
{ 
    ?? 
} 

如何設置監督員下拉用戶從選擇後員工下拉？這裏棘手的部分（至少對我來說）是不得不使用自定義sid而不是員工下拉列表中的值。

Answer 1

function setSupervisor(sender) { 
    var selectedOption = sender.getElementsByTagName("option")[sender.selectedIndex]; 
    var sid = selectedOption.getAttribute("sid"); 

    var supervisorSelect = document.getElementsByName("supervisorID")[0]; 
    for (var i = 0, len = supervisorSelect.options.length, option; i < len; ++i) { 
     option = supervisorSelect.options[i]; 
     if (option.value == sid) { 
      option.selected = true; 
      return; 
     } 
    } 
} 

Answer 2

試試這個：

var empID = document.getElementsByName("empID").item(0); 
var supervisorID = document.getElementsByName("supervisorID").item(0); //This becomes a bit easier if you set an ID as well as a name in your HTML  
var index = empID.selectedIndex; 
var sid = empID.options[index].getAttribute("sid"); 
for(var i=0; i<supervisorID.options.length; i++) 
{ 
    if(supervisorID.options[i].value == sid) 
    { 
     supervisorID.selectedIndex = i; 
     break; 
    } 
}