speedometer prob

yesterday i was drivin my 97 civic ex and i was at a red light. the light turned green and i shifted into first and went and all of a sudden my check engine light came on and my speedometer is dancing around the speeds like crazy. even when i sit still it still goes all over the place...i prob the only car in my hood that does 110 while sittin still lol....and my lights also dim when i hit the gas now anyone have the prob or know whut it might be?

Electric problem... Check your alternator.. Doubt its the batt.