// function for changing font size
// newsize = 'M' | 'L' | 'XL'
function setFontSize(newSize)
{
    // change stylesheet
    changeStylesheets(newSize);

    // change icons
    changeIcons(newSize);
    
    // store preference persistently
    xajax_storeFontSizePreference(newSize);
}


// function for changing font size stylesheets
// newsize = 'M' | 'L' | 'XL'
function changeStylesheets(newSize)
{
    // loop through stylesheets collection
    for (i=0; i < document.styleSheets.length; i++)
    {
        // if this stylesheet has a title
        if (document.styleSheets[i].title)
        {
            // store in separate var
            var t = document.styleSheets[i].title;
            
            // if this is a stylesheet associated with the new font size, enable it
            if (t.substring(0,newSize.length) == newSize)
            {
                document.styleSheets[i].disabled = false;
            }
            // otherwise, disable it
            else
            {
                document.styleSheets[i].disabled = true;    
            }
        }
    }
}

// function for changing switch font size images
// newsize = 'M' | 'L' | 'XL'
function changeIcons(newSize)
{
    // retrieve hanle to images
    var imgM = document.getElementById("imgM");
    var imgL = document.getElementById("imgL");
    var imgXL = document.getElementById("imgXL");
    
    // change img src
	switch (newSize)
	{
		case 'M':
			 imgM.src='images/btn_style_m_actief.gif';
			 imgL.src='images/btn_style_l.gif';
			 imgXL.src='images/btn_style_xl.gif';	
			 break;
		case 'L':
			 imgM.src='images/btn_style_m.gif';
			 imgL.src='images/btn_style_l_actief.gif';
			 imgXL.src='images/btn_style_xl.gif';	
			 break;
		case 'XL':
			 imgM.src='images/btn_style_m.gif';
			 imgL.src='images/btn_style_l.gif';
			 imgXL.src='images/btn_style_xl_actief.gif';	
			 break;
		default:
			 imgM.src='images/btn_style_m_actief.gif';
			 imgL.src='images/btn_style_l.gif';
			 imgXL.src='images/btn_style_xl.gif';		
			 break;
	}
}