Conditionally Hiding Worksheets

I have what on the outset seemed a fairly basic task. In VBA I wanted to conditionally hide worksheets based on a value in my main worksheet.

I have 1 "main interface" worksheet with quite a few "result" worksheets as part of my workbook. Instead of scrolling left and right in the tabs menu everytime I wanted to veiw a particular worksheet I wanted to rather hide all the worksheets except the "main interface" and the relevant "result worksheet", which excel would identify based on a value in my main worksheet.

I wrote the following VBA code to do this but for some reason I cannot get it to work correctly. Perhaps I have made a simple logic error? I am fairly new to VBA. Any advice? ......