summation - Induction proof concerning a sum of binomial coefficients: $sum_{j=m}^nbinom{j}{m}=binom{n+1}{m+1}$

I'm looking for a proof of this identity but where j=m not j=0

http://www.proofwiki.org/wiki/Sum_of_Binomial_Coefficients_over_Upper_Index

$$\sum_{j=m}^n\binom{j}{m}=\binom{n+1}{m+1}$$