function galeria_imagenes(url_imagenes,num)
{
	this.constante=9;
	this.indice=1;
	this.num_imagenes=num;
	this.num_imagenes_restantes=num;
	this.url=url_imagenes
	this.url_g=url_imagenes+"350/";
	this.url_p=url_imagenes+"100/";
	
	this.cambiaTexto=cambiaTexto;
	this.inicio=inicio;
	this.up=up;
	this.down=down;
	this.change_up_p=change_up_p;
	this.change_down_p=change_down_p;
	this.change_g=change_g;
	this.paginas=paginas;
	this.write_paginadores=write_paginadores;
	this.change_number_pag=change_number_pag;
	this.change_to_number_pag=change_to_number_pag;
	this.write_img_big=write_img_big;
	this.write_img_small=write_img_small;
	this.write_diapositivas_actuales=write_diapositivas_actuales;
}
	
function write_diapositivas_actuales(){
	var cad="";
	cad=this.indice;
	cad=cad+" - ";
	if (this.indice+this.constante <= this.num_imagenes){
		cad=cad+(this.indice+this.constante-1);
	}
	else {
		cad=cad+this.num_imagenes;
	}
	cad=cad+" / "+this.num_imagenes;
	document.getElementById("diapositivas").innerHTML=cad;
	}	
	
function cambiaTexto(id,newTexto){ 
	document.getElementById(id).value=newTexto; 
} 	
	
function inicio(){
	this.num_imagenes_restantes-=this.constante;
}	
	
function up() {
	for(i=1;i<=this.constante;i++){
		document.getElementById("imagen"+i).src=String(this.url_p+"Diapositiva"+(this.indice+i-1)+".jpg");
		document.getElementById("imagen"+i).alt=String("Diapositiva"+(this.indice+i-1));
		cambiaTexto("texto"+i,(this.indice+i-1));
	}
}	
	
function down() {
	for(i=1;i<=this.constante;i++){
			document.getElementById("imagen"+i).src=String(this.url_p+"Diapositiva"+(this.indice-(this.constante-i+1))+".jpg");
			document.getElementById("imagen"+i).alt=String("Diapositiva"+(this.indice-(this.constante-i+1)));
			document.getElementById("imagen"+i).style.cursor="pointer";
			document.getElementById("imagen"+i).style.border="1px solid #B2C5D7";
			cambiaTexto("texto"+i,(this.indice-(this.constante-i+1)));
	}	
}
	
function change_up_p() {
		
			if (this.num_imagenes_restantes>=this.constante){
				this.indice+=this.constante;
				this.num_imagenes_restantes-=this.constante;
				this.up();
			}
			else{
				if (this.num_imagenes_restantes!=0) {
					var resto=this.num_imagenes_restantes;
					this.indice+=this.constante;
					for (i=1;i<=(resto);i++){
						document.getElementById("imagen"+i).src=String(this.url_p+"Diapositiva"+(this.indice+(i-1))+".jpg");
						document.getElementById("imagen"+i).alt=String("Diapositiva"+(this.indice+(i-1)));
						cambiaTexto(("texto"+i),String(this.indice+(i-1)));
					}
					while((this.constante-resto)!=0){
						document.getElementById(String("imagen"+(resto+1))).src=String("/images/vacio.gif");
						document.getElementById(String("imagen"+(resto+1))).alt="";
						document.getElementById(String("imagen"+(resto+1))).style.border="1px solid #FFFFFF";
						document.getElementById(String("imagen"+(resto+1))).style.cursor="default";
						cambiaTexto("texto"+String(resto+1),"");
						resto++;
					}
					this.num_imagenes_restantes=0;
				}
			}
			//document.getElementById("traza").value=this.num_imagenes_restantes
			this.write_diapositivas_actuales();
}

function change_down_p() {
		if (((this.num_imagenes%this.constante)==0)&&(this.num_imagenes_restantes==0)){
			this.down();
			this.indice-=this.constante;
			this.num_imagenes_restantes+=this.constante;
		}
		else{
			if (((this.num_imagenes%this.constante)!=0) && (this.num_imagenes_restantes==0)){
				this.down();
				this.indice-=this.constante;
				this.num_imagenes_restantes=this.num_imagenes%this.constante;
			}
			else{
				if (this.indice!=1){
					this.down();
					this.indice-=this.constante;
					this.num_imagenes_restantes+=this.constante; 
					//document.getElementById("traza").value=num_imagenes_restantes;
				}
			}
	  }	
		this.write_diapositivas_actuales();
}

function change_g(src_imagen){
	if ((src_imagen+this.indice)<=this.num_imagenes){
		document.getElementById("imagen_central").src=this.url_g+"Diapositiva"+(src_imagen+this.indice)+".jpg";
		document.getElementById("imagen_central").alt="Diapositiva"+(src_imagen+this.indice);
		}
}

function paginas(){
	var pag;
	if ((this.num_imagenes%this.constante)==0){
	pag=(this.num_imagenes/this.constante);
	}
	else{
		pag=Math.round((this.num_imagenes/this.constante)+0.5);
	}
		return pag;
}


function change_number_pag(jump){
	if (this.num_imagenes_restantes==0){
		var pag=this.paginas();	
	}
	else{
		var pag=Math.round((this.num_imagenes-this.num_imagenes_restantes)/this.constante);
	}
	if (pag<jump){
		var times=(jump-pag)-1;
		this.indice+=(this.constante*times);
		this.num_imagenes_restantes-=times*this.constante;
		//alert(this.indice +"<-indice ### num_imagenes_restantes->"+this.num_imagenes_restantes );
		this.change_up_p();
		//alert(this.indice +"<-indice # num_imagenes_restantes->"+this.num_imagenes_restantes );
	}
	if (pag>jump){
		var times=(pag-jump)-1;
		if (times==1){
			this.change_down_p();
		}
		else{
			this.indice-=(this.constante*times);
			this.num_imagenes_restantes=(this.num_imagenes-this.indice)-this.constante+1;
			//alert(this.indice +"<-indice ### num_imagenes_restantes->"+this.num_imagenes_restantes );
			this.change_down_p();		
			//alert(this.indice +"<-indice # num_imagenes_restantes->"+this.num_imagenes_restantes );
		}
	}
}

function change_to_number_pag(jump){
	if (this.num_imagenes_restantes==0){
		var pag=this.paginas();	
	}
	else{
		var pag=Math.round((this.num_imagenes-this.num_imagenes_restantes)/this.constante);
	}
	if (pag<jump){
		var times=jump-pag;
		for (var i=1;i<=times;i++){									 
			this.change_up_p();
		}
	}
	if (pag>jump){
		var times=pag-jump;
		for (var i=1;i<=times;i++){									 
			this.change_down_p();
		}
	}
}


function write_img_big(){
	document.write('<img id="imagen_central" src="'+this.url_g+'Diapositiva1.jpg" width="350"  height="263" alt="Diapositivas">');
}

function write_img_small(){
	for (var i=1; i<=this.constante; i++){
		document.write('<div><img id="imagen'+i+'" src="'+this.url_p+'Diapositiva'+i+'.jpg" alt="Diapositivas'+i+'" onClick="Migaleria.change_g('+(i-1)+');" width="100" height="75" style="cursor:pointer"><br><input id="texto'+i+'" type="text" size="3" maxlength="3" disabled="disabled" value="'+i+'"></div>');
		}
}

function write_paginadores(){
	document.write('<a href="javascript:Migaleria.change_down_p()">&laquo;</a>');
	for (var i=1;i<=this.paginas();i++){									 
		document.write('<a href="javascript:Migaleria.change_number_pag('+i+')">'+i+'</a>');
	}
	document.write('<a href="javascript:Migaleria.change_up_p()">&raquo;</a>');
}