/*
* 弹出居中窗口
* $type == 'normal' window.open();
* $type == 'nothing' window.open(); 无工具栏
* $type == 'full' window.open() 全屏无工具栏
* $type == 'modal' showModalDialog();
* $type == 'modeless' showModelessDialog();
*/
function pop_up (type,url,width,height){
	if ( width == undefined ) width = 750;
	if ( height == undefined ) height = 550;
	//alert (width + "|" + height);
	//到中间
	var x = screen.availWidth;
	var y = screen.availHeight;
	var movie_x = (x - width) /2;
	var movie_y = (y - height) /2;
	
	if ( type == 'normal' ){
		window.open(url);
	} else if ( type == 'nothing' ){
		window.open(url,'_blank',"toolbar =no, menubar=no, scrollbars=yes, resizable=yes, location=no, status=yes, width=" + width + ", height=" + height + "', top=" + movie_y + ", left=" + movie_x + "'");
	} else if ( type == 'full' ){
		window.open(url,'_blank',"toolbar =no, menubar=no, scrollbars=yes, resizable=yes, location=no, status=yes, width=" + screen.availWidth-10 + ", height=" + screen.availHeight-10 + ",top=0,left=0");
	} else if ( type == 'modeless' ){
		window.showModalDialog($url,'','dialogHeight=' + height + 'px;dialogWidth=' + width + 'px');
	} else if ( type == 'modal' ){
		window.showModalDialog($url,'','dialogHeight=' + height + 'px;dialogWidth=' + width + 'px');
	}
}