To add and remove data in between 2 listboxes in javascript

I wanted to add or remove data inbetween listboxes by using javascript.
i got code from this following link..
http://www.codeproject.com/KB/aspnet/Listbox_or_combo_box.aspx
but when ever i click add button nothing is happenening....
can u pls tell wht is the meaning of this 2 lines of code
 var varFromBox = document.all(lstbxFrom);
 var varToBox = document.all(lstbxTo);  

pls help me ..thanks in advance.
neha_johnAsked:
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David H.H.LeeCommented:
Hi neha_john,
I've completed the test code there, please see the code snippet.
>>can u pls tell wht is the meaning of this 2 lines of code
 var varFromBox = document.all(lstbxFrom); //<---- this is refer the listbox's source control (from parameters)
 var varToBox = document.all(lstbxTo);   //<---- this is refer the listbox's desstination control
 (from parameters)
<html><head>
<script>
function fnMoveItems(lstbxFrom,lstbxTo)
{
 var varFromBox = document.all(lstbxFrom);
 var varToBox = document.all(lstbxTo); 
 
 if ((varFromBox != null) && (varToBox != null)) 
 { 
  if(varFromBox.length < 1) 
  {
   alert('There are no items in the source ListBox');
   return false;
  }
  if(varFromBox.options.selectedIndex == -1) // when no Item is selected the index will be -1
  {
   alert('Please select an Item to move');
   return false;
  }
  while ( varFromBox.options.selectedIndex >= 0 ) 
  { 
   var newOption = new Option(); // Create a new instance of ListItem 
   newOption.text = varFromBox.options[varFromBox.options.selectedIndex].text; 
   newOption.value = varFromBox.options[varFromBox.options.selectedIndex].value; 
   varToBox.options[varToBox.length] = newOption; //Append the item in Target Listbox
   varFromBox.remove(varFromBox.options.selectedIndex); //Remove the item from Source Listbox 
  } 
 }
 return false; 
}
</script>
</head>
<body>
<form>
code for calling the javascript function:
There are 2 methods of calling the javascript code, they are as under.
1.  Add this code in the pageload
btnMoveRight.Attributes.Add("onclick","return fnMoveItems('ListBox1','ListBox2')");
btnMoveLeft.Attributes.Add("onclick","return fnMoveItems('ListBox2','ListBox1')");
2.  Add this code in the HTML
<input type = "button" id = "btnMoveRight" value="  Right  " onclick = "fnMoveItems('ListBox1','ListBox2')">
<input type = "button" id = "btnMoveLeft" value="  Left  " onclick = "fnMoveItems('ListBox2','ListBox1')"><br><br>
<table>
<tr>
<td>
LEFT:<br>
<select id="ListBox1" multiple style="width:100px">
<option value=1>1</options>
<option value=2>2</options>
<option value=3>3</options>
</select>
</td>
<td>
RIGHT:<br>
<select id="ListBox2" multiple style="width:100px">
<option value=1>5</options>
<option value=2>6</options>
<option value=3>7</options>
</select>
 
</td>
</tr>
</table>
</form>
</body>
</html>

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P_RamprathapCommented:
hi
That means you are creating a object of the control in the page . "VAR" means variable type and "document.all" from all the control in the document , create the object of the control with name "lstbxFrom" and "lstbxTo". From there on you can access the two listbox using the object varFromBox ,varToBox
Thanks
P.Ramprathap
0
neha_johnAuthor Commented:
thanks a lot
0
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