Since $81=3^4$, we have $(3^4)^{\frac12}=3^m$.
Using the property $(a^b)^c=a^{bc}$, we can simplify the left side of the equation to $3^{4\cdot\frac12}=3^m$.
This gives us $3^2=3^m$.
Since the bases are equal, we must have $2=m$.
Therefore, $m=\boxed{2}$.
The answer is: 2
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
$(81)^{\frac12}=3^m$. Find $m$.

### Answer:
