从javascript中的选择框中选择值

Question

I want to get the value of the select box using javascript i have the following code.

html part

<select name="marked" id="marked" onchange="checkdata(this); ">
        <option value="">SELECT</option>
        <option value="all">ALL</option>
        <option value="none">NONE</option>
        <option value="read">READ</option>
        <option value="unread">UNREAD</option>
        </select>

script

<script type="text/javascript">
         function checkdata()
         {
             for(var i=0; i < document.myform.message.length; i++)
             {
                 document.myform.message[i].checked=true;
             }
         }
    </script>

i tried the code

var all = document.myform.marked.options[document.myform.selectedIndex].value;
             alert(all);

no alert is coming

i also tried

 var all= document.getElementById('marked').value;
             alert(all);

alert is coming but the value for every selection in "1"

Answer 1

You missed the '.marked':

var all = document.myform.marked.options[document.myform.marked.selectedIndex].value;
alert(all);

Answer 2

var e = document.getElementById("ctl00_cphContent_ddlVoteType");
            var strOption = e.options[e.selectedIndex].value;

working fine for me. please check

Answer 3

Try

<form method="POST" name="me">
    <select size="1" name="D1"  onChange="checkData()">
    <option value="99">Default</option>    
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
    </select><input type="submit" value="Submit" name="B1"><input type="reset" value="Reset" name="B2"></p>
</form>


 <script Language="JavaScript"><!--
function checkData()
    {

    var myTest  = 
     me.D1.options[me.D1.options.selectedIndex].value;

    ///or me.D1.options[me.D1.selectedIndex].value
     alert(myTest);
     }
</script>

Answer 4

the following code is working for me

Java Script :

    function checkdata()
    {
        alert(document.getElementById('marked').value);

    }   

HTML :

        <select name="marked" id="marked" onchange="checkdata(this);">
        <option value="">SELECT</option>
        <option value="all">ALL</option>
        <option value="none">NONE</option>
        <option value="read">READ</option>
        <option value="unread">UNREAD</option>
    </select>

Answer 5

get the selected value onchange

<script Language="JavaScript">
 function checkdata(marked){

 var marked_value =  marked.value; // store the selected value marked_value 

  alert(marked_value); // do further processing with "marked_value" if needed



}
</script>

for option selects you don't use "checked" that is for radio and checkbox