Using javascript to retrieve selected items in a listbox

[rick.dowdall]

Hello - I need to retrieve selected items in a multi select listbox using javascript. I am using asp.net 2.0 and using callbacks. I have two dropdownlists and a listbox in a cascade. When I click the submit button I need to read the values of the controls using javascript which will then run a sub-routiine in the code behind that queries the database and binds the gridview.

Thanks,

Rick

[A1ien51]

How is JavaScript running serverside code? Ajax?

  var sel = document.getElementbyId("ddlId");
  var optsLength = sel.options.length;
  for(var i=0;i<optsLength;i++){
    if(sel.options[i].checked)alert(sel.options[i].text);
  }

Eric

[astlab]

How is JavaScript running serverside code? Ajax?

  var sel = document.getElementbyId("ddlId");
  var optsLength = sel.options.length;
  for(var i=0;i<optsLength;i++){
    if(sel.options[i].checked)alert(sel.options[i].text);
  }

Eric

Thank you Eric your code was really useful for me, you did a little mistake options can be selected and not checked

  var sel = document.getElementbyId("ddlId");
  var optsLength = sel.options.length;
  for(var i=0;i<optsLength;i++){
    if(sel.options[i].selected)alert(sel.options[i].text);
  }

[rick.dowdall]

Thanks for the code.
Serverside code is run via asynchronous callbacks. Using Microsoft's System.Web.UI.ICallbackEventHandler class