(PHP4 >= 4.0RC2)strnatcasecmp -- Case insensitive string comparisons using a "natural order" algorithm
This function implements a comparison algorithm that orders alphanumeric strings in the way a human being would. The behavior of this function is similar to strnatcmp(), except that the comparison is not case sensitive. For more infomation see: Martin Pool's Natural Order String Comparison page.
Similar to other string comparison functions, this one returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.