Macro command button to hide empty rows

I have a master worksheet which will copy data from several pages on a if lookup formula, if it fails it puts "" in instead.

Can someone help me with the code for a macro that will hide each row if the cell in column A contains "".

The macro will be attached to a command button, so will either need to have a 1 click to hide, second click to unhide. Or have 2 buttons.

I'm not sure if I've explained myself, if not please let me know and I will try to clarify.