Sorted:

problem about friend-Collection of common programming errors

Codeigniter – undefined variable-Collection of common programming errors

How can I generate an API Key in My own Controller in Codeigniter-Collection of common programming errors

Help with undefined index in PHP?-Collection of common programming errors

Using properties defined in the Options constructor within custom methods in mootools-Collection of common programming errors

codeigniter database error in selecting data-Collection of common programming errors

problem about nm-Collection of common programming errors

Why doesn't Mathematica use uniform criteria for validating Options?-Collection of common programming errors

problem about lex-Collection of common programming errors

Slope-intercept equation?-Collection of common programming errors