function ChangePicture(num_new_pic){
	var numpix=parseInt(document.getElementById("numpix").innerHTML);
	var page_name=document.getElementById("page_name").innerHTML;
	var abbrev=document.getElementById("abbrev").innerHTML;
	document.getElementById("currpix").innerHTML=num_new_pic;
	
	document["main_viewer"].src="images/"+page_name+"/"+abbrev+"_"+num_new_pic+"_full.jpg";
	var prev=document.getElementById("prev");
	var next=document.getElementById("next");
	if (num_new_pic==1){
		prev.className="nphide";
		prev.innerHTML="Previous";
	}
	else{
		pm1=num_new_pic-1;
		prev.className="npshow";
		prev.innerHTML="<a href='javascript: void(0);' onClick='ChangePicture("+pm1+");' class=active>Previous</a>";
	}
	if (num_new_pic==numpix){
		next.className="nphide";
		next.innerHTML="Next";
	}
	else{
		pp1=num_new_pic+1;
		next.className="npshow";
		next.innerHTML="<a href='javascript: void(0);' onClick='ChangePicture("+pp1+");' class=active>Next</a>";
	}
	for(j=1; j<numpix+1;j++){
		if (j!=num_new_pic)
			document.getElementById("thumb_"+j).className="thumbnail";
		else
			document.getElementById("thumb_"+j).className="currentthumb";

	}		
	return;


}