var newval = 0;
var numImages = 2;

function imgGal(img_num,pn)
{ if(pn=='next' || pn =='prev' )
      { if(pn=='next')
          { if(newval >=numImages)
                { newval = 0; 
                  document.images['ctrlIMG'].src=gIMG[newval];
                  document.images['num_'+newval].src=sIMG[newval];
                  document.images['num_'+numImages].src=dIMG[numImages];
          }else
                { newval++;
                  document.images['ctrlIMG'].src=gIMG[newval];
                  document.images["num_"+newval].src=sIMG[newval];

                   // reset images to default
                  minus=newval-1;
                  document.images['num_'+minus].src=dIMG[minus];
              } }else
         { if(newval <=0)
               { newval = numImages;
                 document.images['ctrlIMG'].src=gIMG[newval];
                 document.images['num_'+newval].src=sIMG[newval];
                 document.images['num_0'].src=dIMG[0];
          }else
               { newval--;
                 document.images['ctrlIMG'].src=gIMG[newval];
                 document.images['num_'+newval].src=sIMG[newval]; 

                   // reset images to default
                  plus=newval+1;
                  document.images['num_'+plus].src=dIMG[plus];
                 } 
             } }else
     { document.images['ctrlIMG'].src=gIMG[img_num];

         // if same value
        if(img_num == newval )
            {document.images['num_'+img_num].src=sIMG[img_num];
               }else
            {document.images['num_'+img_num].src=sIMG[img_num];
             document.images['num_'+newval].src=dIMG[newval];
                  }

        newval = img_num;

     }
   }