//Function to navigate back.
function GoBack() {
    history.go(-1);
}


// Function to Check/Uncheck all the check boxes
var checkedStatus = false;
function CheckAll() {
    var iLoop = 0;
    var objects = document.getElementsByTagName('input');
    for (iLoop = 0; iLoop < objects.length; iLoop++) {
        var thisObject = objects[iLoop]
        if (thisObject.type == 'checkbox' && thisObject.id.indexOf("CheckInstrument") != -1) {
            thisObject.checked = !checkedStatus;
        }
    }
    checkedStatus = !checkedStatus;
    return false;
}


<!--
function popitup(url) {
	newwindow=window.open(url,'name','height=590,width=500');
	if (window.focus) {newwindow.focus()}
	return false;
}

// -->