function add_link_row()
{
	var total_rows_object = document.getElementById('total_links');
	var links_table = document.getElementById('dl_links_table');
	var select_options = document.getElementById('links_options_text');
	var current_rows = parseInt(total_rows_object.value, 10);
	var new_row_id = current_rows + 1;
	var new_row = links_table.insertRow(current_rows);

	new_row.innerHTML = '<td><select name="dl_label' + new_row_id + '" tabindex="16">' + select_options.value + '</select></td><td><input type="text" name="dl_titl' + new_row_id + '" id="titl' + new_row_id + '" size="30" maxlength="255" tabindex="16" value="" class="post" /></td><td><input type="text" name="dl_link' + new_row_id + '" id="dl_link' + new_row_id + '" size="85" maxlength="255" tabindex="16" value="" class="post" /></td>';
	total_rows_object.value = current_rows + 1;
}

function delete_link_row()
{
	var total_rows_object = document.getElementById('total_links');	
	var current_rows = parseInt(total_rows_object.value, 10);
	if(current_rows == 0){
		return(null);
	}
	var links_table = document.getElementById('dl_links_table');
	links_table.deleteRow(current_rows-1);
	total_rows_object.value = current_rows - 1;
}

function img_preview(url, max_width, max_height){
	var preload_image = new Image();
	var preload_image_url = "./styles/enlighten_mod/theme/images/preload.gif";
	preload_image.src = preload_image_url;
	var i_url = trim(url);
	var lengthValue = i_url.length;
	var preview_object = document.getElementById('image_prev');
	if(lengthValue != 0)
	{
		var url_match = new RegExp();
		url_match.compile("^[A-Za-z]+://[A-Za-z0-9-]+\.[A-Za-z0-9]+");
		if (!url_match.test(i_url))
		{
			preview_object.innerHTML = 'Incorrect url entered.';
			return;
		}
		else
		{
			var preview_image = new Image();
			preview_image.src = url;
			if(!preview_image.complete){
				preview_object.innerHTML = '<img src="' + preload_image_url + '" alt="preload_img" />';
			}
			preview_image.onload = function(){
				image_width = preview_image.width;
				image_height = preview_image.height;
				if(image_width > max_width || image_height > max_height){
					if(image_width > image_height && !(image_height > max_height))
					{
						resize_ratio = image_height/image_width;
						set_width = max_width;
						set_height = resize_ratio*max_width;
					}
					else
					{
						resize_ratio = image_width/image_height;
						set_width = resize_ratio*max_height;
						set_height = max_height;
					}
					preview_object.innerHTML = '<img src="' + url + '" alt="album art" width="' + set_width + '" height="' + set_height + '" />';
					return;
				}
				else
				{
					preview_object.innerHTML = '<img src="' + url + '" alt="album art" />';
				}
			}			
		}
	}
	else
	{
		preview_object.innerHTML = 'Please enter a url above to initiate the preview';
		return;
	}
}

function trim(str){
	s = str.replace(/^(\s)*/, '');
	s = s.replace(/(\s)*$/, '');
	return s;
}