VLookup

I having some difficulty with vlookup. I have a construction form that has two dependent drop down lists. The first drop down allows a user to select a material type (lumber,trim etc) dependent on what is selected in the first drop down the user has the option to select from materials based on the first drop down. E.G if lumber is selected in the first drop down a list of lumber is available in the second drop down. My problem begins when i try to use Vlookup to populate a third cell with the item# that is associated with the material chosen in the second drop down. I have my materials in five different tables with the materials in the left column and the Item # in the right column. Can anyone help me with this. I am new to Excel so i may be missing something basic. I have created other drop downs with Vlookups in this form but not with dependent drop downs using different tables. Please Help!!

Thats it! Thank you so much!