So you don't want pseudo-code? Essentially you want us to do your project for you, I'm all for helping but I'm not going to explicitly write code for you for something so simple that you should be able to experimentally figure it out. Sorry to come off so harsh, but if you want to continue building robots, or any electronics really, you need to learn to experiment and figure out things based off your experiments. I will tell you what i'd do though...
+ throw out the sensor variables, you don't need them if you're just making the bot turn drive straight etc, and they're just wasted cycles
+ Now, because I've never built the $50 robot I don't know what the servo_left ( int ) and servo_right ( int ) functions will necessarily do... so go to that function and figure out what it does, once you understand that function everything else is just mechanics that you can figure out with a little math and some experimentation