extjs 同步ajax调用

//同步ajax调用   
	/**  
	 * 同步ajax调用 返回json Object  
	 *   
	 * @param {}  
	 *            urlStr  
	 * @param {}  
	 *            paramsStr 为字符串键值对形式“key=value&key2=value2”  
	 * @return {} 返回json Object  
	 */  
	function ajaxSyncCall(urlStr, paramsStr) {   
	    var obj;   
	    var value;   
	    if (window.ActiveXObject) {   
	        obj = new ActiveXObject('Microsoft.XMLHTTP');   
	    } else if (window.XMLHttpRequest) {   
	        obj = new XMLHttpRequest();   
	    }   
	    obj.open('POST', urlStr, false);   
	    obj.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');   
	    obj.send(paramsStr);   
	    var result = Ext.util.JSON.decode(obj.responseText);   
	    return result;   
	}