How to select all Root Branches in checkboxes of Treeview in ASP. NET 2.0

ASP: Treeview id = "treeview1" runat = "server" performanceid = "xmlperformance1" onclick = "client_ontreenodechecked ();" showcheckboxes = "all">

<Databindings>

<Script language = "JavaScript" type = "text/JavaScript">
Function client_ontreenodechecked ()
{
VaR OBJ = Window. event. srcelement;
VaR treenodefound = false;
VaR checkedstate;
If (obj. tagname = "input" & obj. type = "checkbox "){
VaR treenode = OBJ;
Checkedstate = treenode. checked;
Do
{
OBJ = obj. parentelement;
} While (obj. tagname! = "Table ")
VaR parenttreelevel = obj. Rows [0]. cells. length;
VaR parenttreenode = obj. Rows [0]. cells [0];
VaR tables = obj. parentelement. getelementsbytagname ("table ");
VaR numtables = tables. Length
If (numtables> = 1)
{
For (I = 0; I <numtables; I ++)
{
If (tables [I] = OBJ)
{
Treenodefound = true;
I ++;
If (I = numtables)
{
Return;
}
}
If (treenodefound = true)
{
VaR childtreelevel = tables [I]. Rows [0]. cells. length;
If (childtreelevel> parenttreelevel)
{
VaR cell = tables [I]. Rows [0]. cells [childtreelevel-1];
VaR inputs = cell. getelementsbytagname ("input ");
Inputs [0]. Checked = checkedstate;
}
Else
{
Return;
}
}
}
}
}
}
</SCRIPT>