rocknbil - 4:46 pm on Mar 19, 2010 (gmt 0)
I notice that when i pass an empty string in a parameter it works properly but not when there is no parameter.
Kind of answered your own question. :-) A function is not aware of what you're expecting, only what it receives. There is no "associative" flagging (that I know of.) So it just takes them in the order you pass them, like a list array. I don't do .net or c, but do a lot of other languages - when you pass to a function, you're probably doing
$some_result = some_function (1,2,3);
Leaving parameter 4 null.
$some_result = some_function (1,2,NULL,3);
$some_result = some_function (1,2,'',3);