urm for one there is no string type in C, you need to create an array of character arrays (or pointers to a allocated character array). If you are trying to use in C++ then make sure you have #include <string> and are using the 'std' namespace.
If you don't even know how to make strings, you shouldn't be trying to program the PSP. Go learn how to program first, then come back. The PSP (or any game console) is not the place to learn how to program - a general purpose PC is. We also don't give beginner lessons here. This is a place for developers to discuss projects related to the PS2/PSP/PS3.
