I tried removing the control source but the problem is still there. I notice a 'thud' sound (similar sound when an attempt to click a read only textbox) when I click the combo box. At this point the grid becomes inaccessible. The combo box here is used for selecting the salesman code which I use record source type 3-SQL to display the salesman list from a salesman table. By the way, I am making a form for sales invoice. I have codes in the lost focus event of the combobox to display the salesman name in a text box. Then the parent table is selected. Do you see any relation of this to the grid which is used for entering the items sold?
Regards.