function fieldBlur(field_id, default_value){
	if($(field_id).value == ''){
		$(field_id).value = default_value;
	}
}

function fieldFocus(field_id, default_value){
	if($(field_id).value == default_value){
		$(field_id).value = '';
	}
}

function changeImgSrc(id, src){
	$(id).src = src;
}


function isDocument(href){
	var track_files = new Array('.pdf', '.doc', '.PDF', '.DOC');
	for(var f = 0; f < track_files.length; f++){
		if(href.indexOf(track_files[f]) == (href.length - track_files[f].length)){
			return true;
		}
	}

	return false;
}

function excludeUrl(url){
  var excludeUrls = Array();

  for(var l = 0; l < excludeUrls.length; l++){
    if(url.indexOf(excludeUrls[l]) == 0){
      return true;
    }
  }

  return false;
}

function setupExternalLinks() {
  var links = document.getElementsByTagName('a');
  for (var i = links.length; i != 0; i--) {
    var a = links[i-1];
    if (!a.href) continue;

    if ((a.href.indexOf('http') != -1 && a.href.indexOf(window.location.hostname) == -1 && !excludeUrl(a.href)) 
    	|| isDocument(a.href)
        ) {
        a.target = "_blank";

    }
  }
} 

function loadImages(base_path)
{
	ab0=new Image();
	ab0.src=base_path + "/images/nav-about.jpg";
	ab1=new Image();
	ab1.src=base_path +"/images/nav-about-roll.jpg";
	ab2=new Image();
	ab2.src=base_path +"/images/nav-about-on.jpg";   
	
	co0=new Image();
	co0.src=base_path +"/images/nav-communities.jpg";
	co1=new Image();
	co1.src=base_path +"/images/nav-communities-roll.jpg";
	co2=new Image();
	co2.src=base_path +"/images/nav-communities-on.jpg"; 
	
	ne0=new Image();
	ne0.src=base_path +"/images/nav-news.jpg";
	ne1=new Image();
	ne1.src=base_path +"/images/nav-news-roll.jpg";
	ne2=new Image();
	ne2.src=base_path +"/images/nav-news-on.jpg"; 
	
	re0=new Image();
	re0.src=base_path +"/images/nav-resources.jpg";
	re1=new Image();
	re1.src=base_path +"/images/nav-resources-roll.jpg";
	re2=new Image();
	re2.src=base_path +"/images/nav-resources-on.jpg"; 
}


// main nav functions

function navOn(imgName) {
	if (document.images) {
		if (document.images[imgName].src != eval(imgName + '2.src')) {
			document.images[imgName].src = eval(imgName + '1.src');
		}
	}
}

function navOff(imgName) {
	if (document.images) {
		if (document.images[imgName].src != eval(imgName + '2.src')) {
			document.images[imgName].src = eval(imgName + '0.src');
		}
	}
}