Getprimitiveparams script buggy

Ok messing around trying to find a prim parameter using this script

http://secondlife.com/badgeo/wakka.php?wakka=llGetPrimitiveParams

 list GetPrimitiveParams(list input)
 {
     list output;
     integer c = -llGetListLength(input);
     integer flag;
     integer side;
     while(c<0)
     {
         flag = llList2Integer(input, c++); //pop the stack
         if(llListFindList([PRIM_BUMP_SHINY, PRIM_COLOR, PRIM_TEXTURE, PRIM_FULLBRIGHT], [flag]) + 1)
         {
             side = llList2Integer(input, c++); //pop the stack
             if(side == ALL_SIDES)
             {
                 side = llGetNumberOfSides();
                 while(side--) //we return the sides in reverse order, easier to code; runs faster.
                     output += [flag, side] + llGetPrimitiveParams([flag, side ]);
             }
             else
                 output += [flag, side] + llGetPrimitiveParams([flag, side ]);
         }
         else
             output += [flag] + llGetPrimitiveParams([flag]);
     }
     return output;
 }
 //Contributed by Strife Onizuka
 

Prob been awhile since it was added but it errors on the
while(c<0)

any tips?, trying destructive script skills of mine eep, and erk now it errored on something else..heee wops (tries again)

i tested it, seems to work fine, here is what i used

list GetPrimitiveParams(list input)
{
    list output;
    integer c = -llGetListLength(input);
    integer flag;
    integer side;
    while(c<0)
    {
        flag = llList2Integer(input, c++); //pop the stack
        if(llListFindList([PRIM_BUMP_SHINY, PRIM_COLOR, PRIM_TEXTURE, PRIM_FULLBRIGHT], [flag]) + 1)
        {
            side = llList2Integer(input, c++); //pop the stack
            if(side == ALL_SIDES)
            {
                side = llGetNumberOfSides();
                while(side--) //we return the sides in reverse order, easier to code; runs faster.
                    output += [flag, side] + llGetPrimitiveParams([flag, side ]);
            }
            else
                output += [flag, side] + llGetPrimitiveParams([flag, side ]);
        }
        else
            output += [flag] + llGetPrimitiveParams([flag]);
    }
    llOwnerSay(llDumpList2String(output,","));
    return output;
}
//Contributed by Strife Onizuka

default
{
    state_entry()
    {
        llSay(0, "Hello, Avatar!");
    }

    touch_start(integer total_number)
    {
        GetPrimitiveParams([PRIM_POSITION]);
    }
}