// Global object to hold drag information.

var dragObj = new Object();
dragObj.zIndex = 0;

function dragStart(event, id, dox, doy, startx, endx, starty, endy, theAction) {

  var el;
  var x, y, startx, endx, starty, endy;
  
  dragObj.action = theAction;
    
  if(dox){
  	dragObj.dragX = true;
  }else{
  	dragObj.dragX = false;
  }
  
  dragObj.startx = startx;
  dragObj.endx = endx;

  if(doy){
  	dragObj.dragY = true;
  }else{
  	dragObj.dragY = false;
  }

  dragObj.starty = starty;
  dragObj.endy = endy;

  // If an element id was given, find it. Otherwise use the element being
  // clicked on.

  if (id) {
    dragObj.elNode = document.getElementById(id);
  } else {
	dragObj.elNode = getEvent(event);
	
    // If this is a text node, use its parent element.

    if (dragObj.elNode.nodeType == 3){
    	dragObj.elNode = dragObj.elNode.parentNode;
  	}
  }

  // Get cursor position with respect to the page.

  x = getPageCoordinates(event).x;
  y = getPageCoordinates(event).y;

/*  
  if (isIE()) {
    x = window.event.clientX + document.documentElement.scrollLeft
      + document.body.scrollLeft;
    y = window.event.clientY + document.documentElement.scrollTop
      + document.body.scrollTop;
  }
  if (browser.isNS) {
    x = event.clientX + window.scrollX;
    y = event.clientY + window.scrollY;
  }
*/

  // Save starting positions of cursor and element.

  dragObj.cursorStartX = x;
  dragObj.cursorStartY = y;
  dragObj.elStartLeft  = parseInt(dragObj.elNode.style.left, 10);
  dragObj.elStartTop   = parseInt(dragObj.elNode.style.top,  10);

  if (isNaN(dragObj.elStartLeft)) dragObj.elStartLeft = 0;
  if (isNaN(dragObj.elStartTop))  dragObj.elStartTop  = 0;

  // Update element's z-index.

  dragObj.elNode.style.zIndex = ++dragObj.zIndex;

  // Capture mousemove and mouseup events on the page.

  if (isIE()) {
    document.attachEvent("onmousemove", dragGo);
    document.attachEvent("onmouseup",   dragStop);
    window.event.cancelBubble = true;
    window.event.returnValue = false;
  }
  if (isFirefox() || isSafari()) {
    document.addEventListener("mousemove", dragGo,   true);
    document.addEventListener("mouseup",   dragStop, true);
    event.preventDefault();
  }
}

function dragGo(event) {

  var x, y;

  // Get cursor position with respect to the page.

  x = getPageCoordinates(event).x;
  y = getPageCoordinates(event).y;

/*
  if (browser.isIE) {
    x = window.event.clientX + document.documentElement.scrollLeft
      + document.body.scrollLeft;
    y = window.event.clientY + document.documentElement.scrollTop
      + document.body.scrollTop;
  }
  if (browser.isNS) {
    x = event.clientX + window.scrollX;
    y = event.clientY + window.scrollY;
  } 
*/

  // Move drag element by the same amount the cursor has moved.
  if(dragObj.dragX && dragObj.dragY){
  	if(dragObj.startx && dragObj.endx && dragObj.starty && dragObj.endy){
    	if((stripChars(dragObj.elNode.style.left,'px') >= dragObj.startx || stripChars(dragObj.elNode.style.left,'px') <= dragObj.endx) && (stripChars(dragObj.elNode.style.top,'px') >= dragObj.starty || stripChars(dragObj.elNode.style.top,'px') <= dragObj.endy)){
	    	dragObj.elNode.style.left = (dragObj.elStartLeft + x - dragObj.cursorStartX) + "px";
    		dragObj.elNode.style.top  = (dragObj.elStartTop  + y - dragObj.cursorStartY) + "px";
    	}
    }else{
    	dragObj.elNode.style.left = (dragObj.elStartLeft + x - dragObj.cursorStartX) + "px";
    	dragObj.elNode.style.top  = (dragObj.elStartTop  + y - dragObj.cursorStartY) + "px";
    }
  }else{
  	if(dragObj.dragX){
  	  if(dragObj.startx && dragObj.endx){
  	  	//alert(getPageCoordinates(event).x);
  	  	//alert(dragObj.startx);
    	if((getPageCoordinates(event).x >= dragObj.startx && getPageCoordinates(event).x <= dragObj.endx)){
      		dragObj.elNode.style.left = (dragObj.elStartLeft + x - dragObj.cursorStartX) + "px";
  		}
  	  }else{
   		dragObj.elNode.style.left = (dragObj.elStartLeft + x - dragObj.cursorStartX) + "px";
  	  }
  	}
  	if(dragObj.dragY){
  	  if(dragObj.starty && dragObj.endy){
    	if((getPageCoordinates(event).y >= dragObj.starty && getPageCoordinates(event).y <= dragObj.endy)){
      		dragObj.elNode.style.top = (dragObj.elStartTop + y - dragObj.cursorStartY) + "px";
  		}
  	  }else{
      	dragObj.elNode.style.top = (dragObj.elStartTop + y - dragObj.cursorStartY) + "px";
  	  }
  	}
  }
  if (isIE()) {
    window.event.cancelBubble = true;
    window.event.returnValue = false;
  }
  if (isSafari() || isFirefox()){
    event.preventDefault();
  }
}

function dragStop(event) {

  // Stop capturing mousemove and mouseup events.

  if (isIE()) {
    document.detachEvent("onmousemove", dragGo);
    document.detachEvent("onmouseup",   dragStop);
  }
  if (isSafari() || isFirefox()) {
    document.removeEventListener("mousemove", dragGo,   true);
    document.removeEventListener("mouseup",   dragStop, true);
  }
  
  if((dragObj.endx && dragObj.endy) && (getPageCoordinates(event).x >= dragObj.endx && getPageCoordinates(event).y >= dragObj.endy)){
	  if(dragObj.action){
			document.location=dragObj.action;
	  }
  }else{
	  if((dragObj.endx) && (getPageCoordinates(event).x >= dragObj.endx)){
		if(dragObj.action){
		  	//alert(dragObj.action);
			document.location=dragObj.action;
	    }
	  }
	  
	  if((dragObj.endx) && (getPageCoordinates(event).x >= dragObj.endx)){
		if(dragObj.action){
			document.location=dragObj.action;
	    }  
  	  }
  } 	  
}