// JavaScript Document



// Function to create a cookie

function createCookie(name,value,days) {
	if (days) 
		{
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
		}
	else
		{
		var expires = "";
		};
	document.cookie = name+"="+value+expires+"; path=/";
};

// Function to read the value of a cookie

function readCookie(name) 
	{
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for (var i=0;i < ca.length;i++) 
		{
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
		}
	return null;
};


// Function to create a cookie for changing text size view

function TextCookieAccept()
	{
	createCookie("TextCookieAccept", true, 365);
	};


// Function to change the text size
	
function fsize(cssclass,id, isclick)
{
var vfontsize = document.getElementById(id);
if(vfontsize)
	{
	
		if (readCookie("TextCookieAccept")=='true')
			{
				vfontsize.className = cssclass
				createCookie("textsizestyle", cssclass, 365);
				if(isclick=='c') history.go(0); // force the page to reload if text resized
			}
			else
			{
			document.getElementById('light-text').style.display='block';
			document.getElementById('fade-text').style.display='block';
			};
	};
};





// Function to create a cookie for high contrast colour view

function ContrastCookieAccept()
	{
	createCookie("ContrastCookieAccept", true, 365);
	switch_style('hc');
	};

	
	
	
// Function to change from high contrast to low contrast views - switches main and nav css files

function switch_style (css_title) 
{
if (readCookie("ContrastCookieAccept")=='true')
	{
		var i, link_tag;
		link_tag = document.getElementsByTagName("link");
		
		if(link_tag[2].disabled == true)
			{
				var hc = 1;
				link_tag[1].disabled = true;
				link_tag[2].disabled = false;
				link_tag[3].disabled = true;
				link_tag[4].disabled = false;
				// Alter the transparency
				var overlayBlockEl  = 'div.overlayBlockEl';
				var overlayBlockEls = document.getElements(overlayBlockEl);
				for(o = 0; o<overlayBlockEls.length; o++) 
					{
					overlayBlockEls[o].style.opacity = 1;
					overlayBlockEls[o].style.filter='alpha(opacity=100)';
					}
			} 
		else 
			{
				var hc = 0;
				link_tag[1].disabled = false;
				link_tag[2].disabled = true;
				link_tag[3].disabled = false;
				link_tag[4].disabled = true;
				// Alter the transparency
				var overlayBlockEl  = 'div.overlayBlockEl';
				var overlayBlockEls = document.getElements(overlayBlockEl);
				for(o = 0; o<overlayBlockEls.length; o++) 
					{
					overlayBlockEls[o].style.opacity = 0.8;
					overlayBlockEls[o].style.filter='alpha(opacity=80)';
					}
			};
		createCookie("contrast", hc, 365);
	}
else
	{
		document.getElementById('light-contrast').style.display='block';
		document.getElementById('fade-contrast').style.display='block';
	};
};