Can someone please give me detailed steps on how to use ollydbg with NASM? Everytime I try to open a file in ollydbg it keeps telling me its not open or readable? Not sure why. Never used this debugger before. Any help appreciated. Thanks.

Do link your exes by Alink? Ollydbg always worked for me with NASM exex linked by Alink or MS-LINK. Please attach your exe.