I need help with indexed textures

Hi there, I can't get this code to work properly. I've got 2 prims (left & right) that change the textures stored inside the right one which contains the main script.
It means, if we click on the left one it will turn the page back and if the right one is clicked it'll turn to the next 2 pictures.
It works fine, except when it arrives to the last picture or first one.. I want it to be able to ignore clicks on the proper button if we've reached the max/min index.

How can I do it?

Here's the code snippet...

    link_message(integer sender_num, integer num, string msg, key id) 
    {
        if (numberTextures)
        {
            if (("NEXT" == msg) || ("PREV" == msg))
            {
                if ("NEXT" == msg )
                {
//*************** PROBLEM STARTS HERE ***************
            if  ( currentTexture < numberTextures-1 )
                {
                                 currentTexture+=2;
                }
                }
                else
                { //substract one
                    if ( currentTexture < numberTextures-1 && currentTexture!=0 )
                         {
                                currentTexture-=2;
                         }
                        else
                         {                    
                                currentTexture=0;
                         }
                }
                currentTexture = (currentTexture + numberTextures) % numberTextures;
                llSetTexture( llGetInventoryName( INVENTORY_TEXTURE, currentTexture ), 0);
                
                llMessageLinked(LINK_SET,1,(string)llGetInventoryKey(llGetInventoryName(INVENTORY_TEXTURE, currentTexture-3)),NULL_KEY);
//******************************
            }
        }
    }//link_message

Thank you =)

Hi Cris, not sure exactly what you want to do (don't get the 2 textures stuff then the -3 afterwards)...however here is a simple tip : add or substract first then do the checks:

currentTexture += 2;
if (currentTexture > numberTextures-2) currentTexture = numberTextures -2 ;
// or whatever is your limit

currentTexture -= 2;
if (currentTexture < 0) currentTexture = 0;

Try this and let us now