var chkBoxesSelected = 0;

function EnableDisableButton(chkID, btnID, counterID)
{
    if (document.getElementById(counterID) != null)
    {
        var chkBoxesSelectedCounter = document.getElementById(counterID).value;

        if (chkID != '')
        {
            //Check if the button we just clicked is checked, so we can increment our counter
            if (document.getElementById(chkID).checked == true)
                chkBoxesSelectedCounter++;
            else
                chkBoxesSelectedCounter--;  
        }
        
        //Check the counter so we can enable/disable the button.
        if (chkBoxesSelectedCounter > 0)
            document.getElementById(btnID).disabled = false;
        else
            document.getElementById(btnID).disabled = true;

        //Put our new counter value into this hidden text box so that we keep
        // track of it in viewstate.
        document.getElementById(counterID).value = chkBoxesSelectedCounter;
    }
}

var chkIDs = new Array();

function SelectAll()
{
    for (var i = 0; i < chkIDs.length; i++)
    {
        var obj = document.getElementById(chkIDs[i]);
        if (obj != null)
        {
            obj.checked = true;
            obj.onclick();
        }
    }
}

function ClearAll()
{
    for (var i = 0; i < chkIDs.length; i++)
    {
        var obj = document.getElementById(chkIDs[i]);
        if (obj != null)
        {
            obj.checked = false;
            obj.onclick();
        }
    }
}