image1 = new Image();
image1.src = "link_thumbnails_over.png";
image2 = new Image();
image2.src = "link_search_over.png";
image3 = new Image();
image3.src = "link_new_over.png";
image4 = new Image();
image4.src = "menu_cool_stuff_over.png";
image5 = new Image();
image5.src = "menu_papers_over.png";
image6 = new Image();
image6.src = "link_stats_over.png";

//function to validate the form for a photo comment
function validate_comment()
{
	valid = true;
	
	comment = document.getElementById("comment");
	maxlength = 1000;
    if (comment.value.length == 0)
    {
        alert("Please write a comment before attempting to submit.");
        valid = false;
    }
    if (comment.value.length > maxlength)
    {
        alert("Your comment exceeds the maximum length of "+maxlength+" characters.");
        valid = false;
    }

    return valid;
}

comment_form_visible = 0;
function toggle_comment_form()
{
	if(comment_form_visible == 0)
	{
		document.getElementById("comment_form").style.display = "block";
		document.getElementById("comment_toggle").innerHTML = "– Post a Comment";
		document.getElementById("comment_toggle").title = "click to hide comment form";
		comment_form_visible = 1;
	}
	else
	{
		document.getElementById("comment_form").style.display = "none";
		document.getElementById("comment_toggle").innerHTML = "+ Post a Comment";
		document.getElementById("comment_toggle").title = "click to show comment form";
		comment_form_visible = 0;
	}
	
}