InfoPath Dev

Hi, i have a category field with a drop down list-box. There are three items (selections) configured, electrical, mechanical and IT. Once a new form is populated by a user and he/she selects one of these categories i would like to populate the "Assigned To" field with a specific user (lead engineer) responsible for that discipline ie Joe Block looks after IT, if the user selects IT, 'Joe Block' should automatically appear in the 'Assigned To' field. How do i do this? Can you someone please help me with this?

 Sure - you need to add rules to your category field. The first rule would have the condition "Category is equal to electrical" and the action to set a field's value, assigned to, to the test "Joe Block". Repeat for the other category options. Remember that XML / XPath is case sensitive, so Electrical and electrical are not the same thing. If assigned to is a person / group and not just a text field, let me know & I can help you with that too. :)