//Set all checkboxes to one state
function setAllCheckBoxes(sFormName, sFieldName, bCheckValue)
{
    //Return if form doesn't exist
    if (!document.forms[sFormName]) {
        return;
    }

    //Get form checkboxes
    var oCheckBoxes = document.forms[sFormName].elements[sFieldName];

    //Return if no checkboxes
    if (!oCheckBoxes) {
        return;
    }

    //Get checkbox count
    var iCheckBoxesCount = oCheckBoxes.length;

    //If only one checkbox, set it as desired
    if (!iCheckBoxesCount) {
        oCheckBoxes.checked = bCheckValue;
    } else {
        //Parse checkboxes and set them as desired
        for(iCount = 0; iCount < iCheckBoxesCount; iCount++) {
            oCheckBoxes[iCount].checked = bCheckValue;
        }
    }
}