ASP.Net Tree view check uncheck problem.

Recently I faced issue to check UN-check tree view nodes of a multilevel tree bound with SharePoint document library structure. I searched google but could not found any easy solution so decided to resolve it simply on my own. I wrote "TreeNodeCheckChanged" event. From it I called a recursive function.

  private void CheckUnCheck(TreeNodeEventArgs e)
        {
            if (e.Node.ChildNodes != null && e.Node.ChildNodes.Count > 0)
            {
                foreach (TreeNode childNode in e.Node.ChildNodes)
                {
                    if (e.Node.Checked)
                    {
                        if (!childNode.Checked)
                            childNode.Checked = true;                       
                    }
                    else
                    {
                        if (childNode.Checked)
                            childNode.Checked = false;
                    }
                    if (childNode.ChildNodes != null && childNode.ChildNodes.Count > 0)
                    {
                        CheckUnCheck(new TreeNodeEventArgs(childNode));
                    }
                }
            }
        }

this is not done yet. This function wont fire (I don't know why...) so I used a simple trick in Client side called a javascript function like below.

function CheckChangeEvent(event) {
        var obj = null;
        if ((navigator.appVersion.indexOf("MSIE 7.0") > 0) || (navigator.appVersion.indexOf("MSIE 8.0") > 0)) {
            obj = window.event.srcElement;
        }
        else {
            obj = event.target;           
        }
        if (obj == null) {
            alert('Object not found!');
            return false;
        }           
        if (obj != null) {
            if (obj.tagName == "INPUT" && obj.type == "checkbox") {
                __doPostBack(obj.id, '');
            }
            return true;
        }
        else {
            return false;
        }
    }

It do as post back on each click but does the trick... Hope this will help someone.