Adventure Game Studio

Hi guys,

I want a function to loop through a Gui buttons checking if one of them has a given graphic.
If so, switch the graphic with a second given graphic, for a sort of 'what-to-do-notepad-GUI'
with a better look than a GUI list box.

Here's my code


function Assegna_appunto(int imagineA, int imagineB)
{
int i=0;
Button *bottone[30]; //Max number of buttons allowed in one GUI
while(i<=gBlocco.ControlCount)
  {
   if(bottone[i].Graphic==imagineA)
     {
      gBlocco.Visible=true;Wait(40);
      bottone[i].NormalGraphic=imagineB;Wait(40);
      gBlocco.Visible=false;
     }
   else i++;
  }  
}


But when the game calls the function I receive a 'null pointer referenced'.
What exactly am I doing wrong?

Thanks in advance.

EDIT:

Meanwhile I brainstormed and came up with this working code:


function Assegna_appunto(int immagineA, int immagineB)
{
int i;
while(i<gBlocco.ControlCount)
  {
   if(gBlocco.Controls[i].AsButton.Graphic==immagineA)
    {
     gBlocco.Visible=true;Wait(40);
     gBlocco.Controls[i].AsButton.NormalGraphic=immagineB;Wait(80);
     gBlocco.Visible=false;
     return;
    }
   else i++;
  } 
}



Cheers