//Isset function
function isset(varname){
  return(typeof(window[varname])!='undefined');
}

//Function to start/stop playack of the automatic image transitions
function changePlayback(action, image) {
	if (image != undefined) {	
	clearInterval(loop);
	j = image;
	} else {
	j = 1;
	}
	
	if (action == "play") {
	changeTeaser(j);
	loop = setInterval("changeTeaser(j)", 6500);	
	} else if (action == "pause") {
	clearInterval(loop);
	}
}

//Function to change the class of number buttons
function changeClass(image_number) {
	document.getElementById("button_"+image_number).className = "active";
	document.getElementById("button_"+image_number).blur();
	
	if(undefined===window.previous_image){
	window.previous_image = image_number;
	} else {
	document.getElementById("button_"+previous_image).className = "not_active";
	window.previous_image = image_number;
	}
}

function changeImage(i) {
	//Fade new background image into 'main'
	blendimage('main','blendimage', src_array[i-1],800)

	//Change the href value of the image
	document.getElementById('view_project_link').href = "project"+id_array[i-1]+".html";

	//Call the function to generate the navigation panel
    changeClass(i);
}

function changeTeaser(jumpTo) {
	changeImage(jumpTo);
	j++;

	if (j > (src_array.length)) {
	j = 1;
	}
}

var browser=navigator.appName;
if (browser=="Microsoft Internet Explorer"){
	window.onpageshow = changePlayback('play'); preloader(); hideLoadBox();
	window.onload = hideLoadBox;
} else {
	window.onpageshow = preloader(); hideLoadBox();
	window.onload = changePlayback('play');  hideLoadBox();
}