var switch_speed = 5000;
var fade_speed = 50 ;
// Mangler at appende ob_id til class og lave fade speed uglobal, for at lave mulighed for flere på samme side

function create_slide_object(ob_id,width,height,s_speed,f_speed,img_list) {
  if(img_list == "") return;
  
  var img = img_list.split(";");
  if(img.length == 1) {
	  img[1] = img[0] ;
	  img_list = img_list + ";" + img_list ;
  }
  switch_speed = s_speed ;
  fade_speed = f_speed ;
  document.writeln("<div style='position: relative; height:" + height + "px'>") ;
  document.writeln("<div id='" + ob_id + "_slidefrontdiv' style='position: absolute'>")
  document.writeln("<img src='" + img[0] + "' id='" + ob_id + "_imgfront' width='" + width + "' height='" + height + "' class='slideimage_style' />");
  document.writeln("</div>");
  document.writeln("<div id='" + ob_id + "_slidebackdiv' style='position: absolute'>");
  document.writeln("<img id='" + ob_id + "_imgback' src='" + img[1] + "' width='" + width + "' height='" + height + "' class='slideimage_style' />");
  document.writeln("</div>");
  document.writeln("</div>");
  document.writeln("<input type='hidden' id='slide_sw' value='0' />");
  document.writeln("<input type='hidden' id='" + ob_id + "_slide_imglist' value='0' />");

  document.getElementById(ob_id + "_slide_imglist").value = img_list ;
  if ( document.getElementById(ob_id + "_slidebackdiv").filters ) {
	document.getElementById(ob_id + "_slidebackdiv").style.filter = "alpha(opacity=0)";
  } else {
    document.getElementById(ob_id + "_slidebackdiv").style.opacity = 0;
  }
  //alert(document.getElementById("imgfront").src);
  setTimeout("switch_image ('" + ob_id + "',0,0,1)",switch_speed)
}

function switch_image (ob_id,step,side,imgnr) {
  if(step >= 100) {
	 // skift billedet
	 imgnr += 1;
	 var imgarray = document.getElementById(ob_id + "_slide_imglist").value.split(";");
     if(imgnr > imgarray.length - 1) imgnr=0 ;	
     if(side == 0) {
	   side = 1;
	   document.getElementById(ob_id + "_imgfront").src = imgarray[imgnr];
	 } else {
	   side = 0 ;
       document.getElementById(ob_id + "_imgback").src = imgarray[imgnr];
	 }
     setTimeout("switch_image ('" + ob_id + "',0," + side + "," + imgnr + ")",switch_speed)
     return;
  }
  // lav billedfade
  step +=5;
  if(side == 0) {
    setOpacity( document.getElementById(ob_id + "_slidebackdiv"), step );
  } else {
    setOpacity( document.getElementById(ob_id + "_slidebackdiv"), 100 - step );

  }
  setTimeout("switch_image ('" + ob_id + "'," + step + "," + side + "," + imgnr + ")",fade_speed)
}

function setOpacity( elem, level ) {
    if ( elem.filters ) elem.style.filter = "alpha(opacity=" + level + ")"
    else elem.style.opacity = level / 100;
}