..bike is standing...need advice...

I had to cage today because my bike is standing at home. The engine goes dead every time I touch the throttle, even if I twist it only 1mm the engine goes dead. The only thing I can think of is either it's flooding, or the spark plug needs to be replaced. So, what do I need to do? Clean the air-filter? Adjust something on the carburetor? Replace the spark plug, or all of the above? I seriously need advice, so could someone that's had the same problem please reply.

P.S. Just a random thought, but could it be valve clearance?