Bad luck...

Just now yam char with my fren....when wanna go back that time..my car cant even start enjin..i though is my car key no battey so i call my dad ask for help.....i like so poh wait there till 20min....then my dad pass me another car key, so i try to open it but still cant....my dad say no more battery lo..haiz i need to buy new one to replace it...so bad luck ler summore now no money ler...haiz