Selecting Cell in a ListBox

The sample code below the render method from my GridRowRenderer which implements RowRenderer.
The data in this case is a 2 dimensional array so that my grid has 2 columns of data. If you follow along in the code
you can see that depending upon if images are found etc. I add different component types into each grid column and row.



Here are the two .css classes used by this code : 

.userButton
{	
    border: none;
    font-size: xx-small; 
    font-weight: normal;
    background : transparent;
    font : icon;		
}

.unknownUserImage
{
    background : URL(./images/user/UnkownUserSmall.jpg) no-repeat center;
    border: none;
    font: icon;
    font-size:xsmall;
    height : 32px;
    width : 32px;
}



	public void render(Row row, Object rowData) throws Exception
	{
				
		try
		{
			
			// for a user gird, we are expecting 2 rows of data, a 2 dimensional array.
			DHeUser[] userRowData = (DHeUser[])rowData;
			
			// 2 Columns of data
			DHeUser user1 = userRowData[0];
			DHeUser user2 = userRowData[1];
			if (user1 != null)
			{
                                // Look in the database for an image for this user
				org.zkoss.image.Image zkImage = DHzZKUtilities.getZKImageForUser(user1);
                                // Create the button that is going in column1 and give it a label equal to the username
				Button userButton1 = new Button(user1.getUserName());
                                // If we found an image for this user we set it into the button
				if (zkImage != null)
				{
					userButton1.setImageContent(zkImage);
					userButton1.setSclass("userButton");
					userButton1.setParent(row);					
				}
				else // If we don't have an image in the DB for this user. We use the unknownUserButton sclass
				{
			                Vbox vbox = new Vbox();
			                vbox.setPack("center");    
			                vbox.setAlign("center");					
							userButton1.setSclass("unknownUserButton");	
							userButton1.setLabel("");
							userButton1.setParent(vbox);					
			                Label buttonLabel = new Label(user1.getUserName());
			                buttonLabel.setSclass("dhUISmallIconFont");
			                buttonLabel.setParent(vbox);		                
			                vbox.setParent(row);
				}
				userButton1.setWidth(new String(componentWidth + "px"));
				userButton1.setId("usergridbuttonColumn1" + System.currentTimeMillis() + DHzZKUtilities.seperator + user1.getId());
				userButton1.addEventListener("onClick", userSelectListener);				
				userButton1.setOrient("vertical");
				
			}
			else
			{
				Label emptyLabel = new Label();
				emptyLabel.setParent(row);
			}
			if (user2 != null)
			{ 
				org.zkoss.image.Image zkImage = DHzZKUtilities.getZKImageForUser(user2);				
				Button userButton2 = new Button(user2.getUserName());
				if (zkImage != null)
				{
					userButton2.setImageContent(zkImage);
					userButton2.setSclass("userButton");
					userButton2.setParent(row);		
				}				
				else
				{
			                Vbox vbox = new Vbox();
			                vbox.setPack("center");    
			                vbox.setAlign("center");					
							userButton2.setSclass("unknownUserButton");	
							userButton2.setLabel("");
							userButton2.setParent(vbox);					
			                Label buttonLabel = new Label(user2.getUserName());
			                buttonLabel.setSclass("dhUISmallIconFont");
			                buttonLabel.setParent(vbox);		                
			                vbox.setParent(row);
				}
				userButton2.setWidth(new String(componentWidth + "px"));
				userButton2.setId("usergridbuttonColumn2" + System.currentTimeMillis() + DHzZKUtilities.seperator + user2.getId());
				userButton2.addEventListener("onClick", userSelectListener);						
				userButton2.setOrient("vertical");				
			}			
			else
			{
				Label emptyLabel = new Label();
				emptyLabel.setParent(row);
			}						
		}
		catch(Exception e)
		{
			logger.error("DHzUserGridRowRenderer render method. Exception caught : " + e.getMessage(),e);
			throw e;
		}		
	}