Datagrid problem

Hi,

I am using datagrid and added 3 columns to it in flex project. Data is provided to each column by using itemrenderer. Itemrenderer is checkbox for each column. Name of columns are col1,col2,col3. I want to make the checkbox in col1 selected when i selects the checkbox in col2. But i am not able to do this. If anyone have the solution for this ,please provide me.

Regards

Kotland