Trying to dual monitor with DVI and a HDMI GeForce GT220?

Hello, im trying to dual monitor with a DVI and a HDMI but my tv says connecting to it but no display is being shown and my check my properties also says not detected.|||By dual monitor, i'm going to assume you already have at least "one" monitor hooked up correctly to your pc. K so after you hook it up, go to nvidia control panel ( you can do this by going to your desktop, right clicking anywhere and then click nvidia control panel ) then go to set up multiple displays and select which one you want...dual view/clone/expand/etc