Start Building Professional
Web Apps Today

problem loading tabbar with 2 grids (Urgent please)

Hello,
I have a tabbar with 2 tabs. each one contain a grid
tabbar=new dhtmlXTabBar('a_tabbar','left');
tabbar.setImagePath('/common/components/dhtmlxTabbar/imgs/');
tabbar.setSkinColors('#FCFBFC','#F4F3EE');
//tabbar.setStyle("silver");
tabbar.addTab("a1","UserName","100px");
tabbar.addTab("a2","ContactList","100px");
tabbar.setContent('a1','mygrid');
tabbar.setContent('a2','mygrid2');
tabbar.setTabActive('a1');

when loading the page i'm having as error : A runtime error has occured
line:1396
error:'this._contents[...]'is null or not an object


how to resolve the problem ?

The problem caused by incorrect object name , please be sure that HTML elements with names 'mygrid' and mygrid2' exist on moment of command call. 
( You can check the sample at  http://dhtmlx.com/docs/products/kb/index.shtml?cat=recent&q=4768 )