void check(char oil[j])<br>   </pre>   <br>is wrong since you tell you use i and j but you do not define them as parameters. The compiler doesn't understand what you are trying to do and doesn't know what the symbols i and j are if you do not define them. The compiler doesn't infer any meaning from pre- or post-existing code: it interprets each line separately into a stream of tokens.<br><br>Looking at your program you have global variables (oil, m, n, wait, oilnum). These can be accessed from everywhere. You seem to have a problem with local variables and scope of variables. Your use of i and j shows such a misunderstanding.<br><br>For your program, you define i and j within two for loops. The scope of i and j are thus restricted inside the curly braces of the for loops. When you call your function check, you enter another scope where i and j are not defined (from the compiler side, the i and j within the check function and the i and j within the for loops are not the same eventhough you use the same symbol to describe them). Thus you need to define i and j within the scope of your function. Since you need the position within the oil field, you need to pass as parameters the i and j variables. Your function header then becomes:<br><br>void check (int i, int j)<br><br>You do not need to pass oil as a parameter since it is a global variable.<br><br>Imagine now you want to pass oil as a parameter. What is the type of oil ? Oil is obviously an array but how does the computer store an array ? The computer has no understanding of dimension: its memory is just a stream of cells where you can store any kind of information. To be able to store or access that information, you need to tell the computer the type of the information so that it can correctly retrieve the data stored in memory.<br>You do not only store data in memory, but you also can store memory adresses.<br><br>Ok, now how does the computer store a multidimensional array ? When you look at your oil array, you are looking  at a pointer to an area of memory. The type of oil is char**. What does that mean ? When you write<br><pre> <br>a = x where a is an array of Type<br>   </pre>   <br>the computer understands <br><pre><br>*(a + i*sizeof(Type)) = x<br>   </pre>   <br>it takes the starting adress of a, adds the index number times the size of the type to point to the correct memory area then retrieves the value stored at that memory adress. If you do not understand the notion, I would suggest you to look at pointers.<br><br>I strongly advise you to look at your manual to understand how everything works and to find out any documentation you can find (look on internet if you don't have access to introductory programming books).       <br><br>Ghostly yours,<br>Red.   <br><br><SPAN CLASS=editedby>[edited by - Red Ghost on May 19, 2004 3:04:49 AM]</SPAN>   <br><br><SPAN CLASS=editedby>[edited by - Red Ghost on May 19, 2004 3:05:21 AM]</SPAN>