Let V a norma space with 2 norms , lets say norm 1 and norm 2

Show that the function identity $\displaystyle $\ I_d :\left( {V,\left\| x \right\|_1 } \right) \to \left( {V,\left\| x \right\|_2 } \right)\$$ es continuos iff the set

A$\displaystyle \A = \left\{ {x \in V/\left\| x \right\|_1 = 1} \right\}\$$ is bounded with norm 2

Please somebody give me a biiiiiiiiiiiiig hint....

Regards...