index1 = 0;
			    function more_images(step,numgal,files) {
			        index1 = index1 + step;
			        document.getElementById("im1").src = "gallery/images/gallery/" + numgal+"/" + (index1*2+1).toString() + ".jpg";
			        document.getElementById("im2").src = "gallery/images/gallery/" + numgal+"/" + (index1*2+2).toString() + ".jpg";
			        document.getElementById("im3").src = "gallery/images/gallery/" + numgal+"/" + (index1*2+3).toString()+".jpg";
			        document.getElementById("im4").src = "gallery/images/gallery/" + numgal+"/" + (index1*2+4).toString() + ".jpg";

			        document.getElementById("h1").href = "gallery/images/gallery/" + numgal+"/" + (index1 * 2 + 1).toString() + ".jpg";
			        document.getElementById("h2").href = "gallery/images/gallery/" + numgal+"/" + (index1 * 2 + 2).toString() + ".jpg";
			        document.getElementById("h3").href = "gallery/images/gallery/" + numgal+"/" + (index1 * 2 + 3).toString() + ".jpg";
			        document.getElementById("h4").href = "gallery/images/gallery/" + numgal+"/" + (index1 * 2 + 4).toString() + ".jpg";


			        if (index1 ==0) {
			            document.getElementById("arrow_l").style.visibility = "hidden";
			            document.getElementById("hal").style.visibility = "hidden";
			        }
			        else {
			            document.getElementById("arrow_l").style.visibility = "visible";
			            document.getElementById("hal").style.visibility = "visible";
			        }


			        document.getElementById("arrow_r").style.visibility = "visible";
			        document.getElementById("har").style.visibility = "visible";

			        if (index1*2+1>files)
			            document.getElementById("im1").style.visibility = "hidden";
			        else 
			            document.getElementById("im1").style.visibility = "visible";


			        if (index1 * 2 + 2 > files)
			            document.getElementById("im2").style.visibility = "hidden";
			        else
			            document.getElementById("im2").style.visibility = "visible";


			        if (index1 * 2 + 3 > files)
			            document.getElementById("im3").style.visibility = "hidden";
			        else
			            document.getElementById("im3").style.visibility = "visible";


			        if (index1 * 2 + 4 > files) {
			            document.getElementById("im4").style.visibility = "hidden";
			            document.getElementById("arrow_r").style.visibility = "hidden";
			            document.getElementById("har").style.visibility = "hidden";
			        }
			        else
			            document.getElementById("im4").style.visibility = "visible";
			        

			    }