var previous_hightlighted= "td_0";

function previewData(index){

	
	var preview_img = document.getElementById("preview_img");
	var preview_title = document.getElementById("preview_title");
	var preview_Description = document.getElementById("preview_Description");
    var preview_viewNow = document.getElementById("preview_link");
	
	var desc = document.getElementById("desc_" + index);
	var img = document.getElementById("img_" + index);
	var subject = document.getElementById("subject_" + index);
	var viewnow = document.getElementById("viewNow_" + index);
	
	
	//replacing data
	preview_img.src = img.src;
	preview_title.innerHTML = subject.innerHTML;
	preview_Description.innerHTML = desc.innerHTML;
	preview_viewNow.innerHTML = viewnow.innerHTML;
	
	
	//hightlight
	previousTD = document.getElementById(previous_hightlighted);
	if(previousTD.className.indexOf("td_current") >= 0){
	   previousTD.className = previousTD.className.substring(0, previousTD.className.indexOf("td_current"));
	}
	
	var currentTD = document.getElementById("td_" + index);
	currentTD.className += " td_current"; 
	previous_hightlighted="td_" + index;
	
}