if statement with isblank and if greater than

[trosasco23]

How do I add an ISBLANK to this formula?

=IF(A$1>A2,(A1-A2),0)

So this formula is to calculate this:

If my cell in A1 is larger than the one below, then A1 minus A2, if not 0... but what if there is nothing on A2.. I would like it to come back blank.

a1 = $2000 amount to be paid
a2 = $1000 amount paid
a3 = blank

b2 = is the difference (will be $1000)
b3 = should be BLANK

[protonLeah]

=if(isblank(a2),"",max(a1-a2,0))

[trosasco23]

Thank you Ben.. It didn't work as I needed it to but thanks again.