// Controls auto slide show
// Parameters

// Image Max dimensions
var AimgMaxWidthpx = 300; var AimgMaxHeightpx = 225;
var AimagePath = "master/slide/";
var pause = 4000;
var AutoLength =0; 

//**********************************************************************************************

// create array for anchors
var Aslide_ImageLink = new Array ("master/perl/getimage.pl?imageID=01059","master/perl/getimage.pl?imageID=01125","master/perl/getimage.pl?imageID=01133","master/perl/getimage.pl?imageID=01197","master/perl/getimage.pl?imageID=01217");
// create array for Titles
var ASlide_Title_arr = new Array ("Ideal Territory","Boulters Lock ","Eton College","Tower Bridge","Greenwich Park");
// create array for alt text
var Aslide_alt_Text = new Array ("Ideal Territory  Acrylic on Board 40x56cm","Boulters Lock Watercolour 56x38cm","Eton College Watercolour 39x53cm","Tower Bridge Watercolour 50x34cm","Greenwich Park Watercolour 56x38cm");
// create an array of image file names values in these arrays inserted by VB
var Aslide_images = new Array ("01059-otters-ideal-territory.jpg","01125-boulters-lock.jpg","01133-eton-college.jpg","01197-south-bank-view-of-tower-bridge-and-hms-belfast.jpg","01217-greenwich-park.jpg");
Aslide_alt_Text.toString();
// Only used to allocate cache memory for images
var Aslide_width = new Array ("169","300","172","300","300");
var Aslide_height = new Array ("255","203","225","207","198");

// preload all slide the images
var AUTOslide = new Array();
for( var i = 0; i < Aslide_images.length; i++ ){
        AUTOslide[i] = new Image(Aslide_width[i],Aslide_height[i]);
        AUTOslide[i].src = AimagePath + Aslide_images[i];
        if (AUTOslide[i].naturalWidth > AimgMaxWidthpx){
                
                alert("Image " + ASlide_Title_arr[i] + " is " + AUTOslide[i].naturalWidth + "px exceeds allowed " + AimgMaxWidthpx + "px width");
        }
        if (AUTOslide[i].naturalHeight > AimgMaxHeightpx){
                alert("Image " + ASlide_Title_arr[i] + " is " + AUTOslide[i].naturalHeight + "px exceeds allowed " + AimgMaxHeightpx + "px height");
        }
}

function AutoUpdateImage(NDX){
        // Update Title
        document.getElementById("AStitle").firstChild.nodeValue = ASlide_Title_arr[NDX];
        // Initalise Image
        var oldimg = document.getElementById("ASlidepic").firstChild;
        var newimg = document.createElement("img");
        newimg.src = AUTOslide[NDX].src;
        // Swap image
        document.getElementById("ASlidepic").replaceChild(newimg,oldimg);   
        // Create link to picture page.
        document.getElementById("ASimagelink").setAttribute('href',Aslide_ImageLink[NDX]);
        // Create Title text & alt text
        document.getElementById("ASimagelink").setAttribute('title',Aslide_alt_Text[NDX]);
        document.getElementById("ASimagelink").setAttribute('alt',Aslide_alt_Text[NDX]);
}

var  pic_pointer =0;
function rotate(){
	 
	 var lastpointer=pic_pointer;
	 
        AutoLength = Aslide_ImageLink.length;
	while (pic_pointer == lastpointer){
		pic_pointer =(Math.ceil(Math.random() *--AutoLength));
	}
      AutoUpdateImage(pic_pointer) ;       
                  
  window.setTimeout( "rotate()", pause );                              
}