Cascading Combo boxes

Hi,

I recently studied the introduction & intermediate access 2010 course with stl-training.co.uk and at the time it all made sense, however I am trying to put this knowledge into action but am failing somewhere.

What I am trying to achieve is a form whereby there are 2 combo boxes, one that says machinetype, the other that says machinename.

I would like it so that when you select a machinetype, the only machinenames that are available in the second combo box are directly related to the machinetype that was selected on the first combobox. However, I am struggling and cannot get this to work.

I suspect I may be getting the relationship between my two tables wrong but dont know where to start to troubleshoot.

Can someone let me know what I should be checking to try and indentify the problem and its solution.

Thank you.

Steve.