I wish to number my theorems within subsections as
And only reset it back to 1 when I have a new subsection.
So I have a subsection within a section, and within the subsection I have several theorems, which are normally numbered section.subsection.theoremnumber. But I want it just to be Theorem 1, Theorem 2, Theorem 3, etc until the end of the subsection, and in the next subsection, reset it back to Theorem 1, Theorem 2, etc.
How can I do this?