// Function name: popup()
// Parameters:
// 	url    - The URL of the popup.
function popup(url) {
	var winHeight = 450
	var winWidth = 700
	var showscrollbar = "yes"
	
	// only set the height and width if both are specified
	if (popup.arguments.length > 2) {
		winHeight = popup.arguments[1];
		winWidth = popup.arguments[2];
	}
	
	// set whether to show vertical scrollbar
	if (popup.arguments.length > 3) {
		showscrollbar = ((popup.arguments[3] == true)?"yes":"no");
	}
	
	window.open(url,"","scrollbars=" + showscrollbar + " ,height=" + winHeight + ",width=" + winWidth + ",left=50,top=50");
}