function open_window( pageToLoad, width, height) {

	// check if browser 4 or above
	isVer4Min = parseInt(navigator.appVersion) >= 4;
	
	
	// calculate (centered) window position
	xposition=0;
	yposition=0;
	if (isVer4Min) {
		xposition = (screen.width - width) / 2;
		yposition = (screen.height - height) / 2 - 20;
	}
	
	// build arguments list
	args = "width=" + width + ","
	+ "height=" + height + "," 
	+ "location=0," 
	+ "menubar=0,"
	+ "resizable=1," 
	+ "scrollbars=1,"
	+ "status=0,"
	+ "titlebar=0,"
	+ "toolbar=0,"
	+ "hotkeys=0,"
	+ "screenx=" + xposition + "," //NN Only
	+ "screeny=" + yposition + "," //NN Only
	+ "left=" + xposition + "," //IE Only
	+ "top=" + yposition; //IE Only


	// open window	
	if(isVer4Min){
			popup = window.open(pageToLoad,'sitema',args);
			popup.focus();
	}

/* 	alert(args); */
}