Checking State of Mouse button

[stupomer]

Hi,
I feel I should know this but couldn't figure it out or find it in the forum.

Is it possible to check a mouse button state and then run code depending on that state (1 verus 0)?

This is different than mouse chording.

Related question:

In the wait dialog, it offers "Wait for Key Up" and "Wait for Key Down"
but only offers "Wait for Mouse Button Up"
Is there a reason for this? Can I have a wait for a click down on a mouse button?

Thanks so much!!!!

Stuart