Select by Location with user input

Hey everybody,

I have been fighting with this for a while. I was looking to create a button that starts a select by location script with the highlighted parts of select by attribute being configured by the user.

In example: The user clicks on the button and a popup box appears asking the user to select the layers he would like as target features (in_layer). These features are all found in the table of contents.
After selecting the layers another box pops up directing him to select the "select feature" layer (which there is a choice of 5 specific layers). These features are not in the table of content but in a geodatabase.


SelectLayerByLocation_management (in_layer, {overlap_type}, {select_features}, {search_distance}, {selection_type})

Any help is appreciated!