function decreaseFontSizeInDiv(elId, relSizeFieldId) {
	increasedecreaseFontSizeInDiv(elId, relSizeFieldId, -1);
}

function increaseFontSizeInDiv(elId, relSizeFieldId) {
	increasedecreaseFontSizeInDiv(elId, relSizeFieldId, 1);
}

function increasedecreaseFontSizeInDiv(elId, relSizeFieldId, chngValue) {
	var maxInc = 5;
	var maxDec = -3;
	var tagsForChange = new Array("span", "p", "ul", "h1", "h2", "h3", "h4", "h5", "h6");

	if ($("#" + elId).css("font-size") != undefined) {
	    var oldFontSize = parseInt($("#" + elId).css("font-size").replace("px", ""));
	    var newFontSize = Math.round(oldFontSize + (oldFontSize * chngValue / 10)) + 'px';
	    $("#" + elId).css("font-size", newFontSize);
	}
	
	var relSizeField = document.getElementById(relSizeFieldId);
	var relFontSizeNew = parseInt(relSizeField.value) + chngValue;

	if (relFontSizeNew <= maxInc && relFontSizeNew >= maxDec) {
		relSizeField.value = relFontSizeNew;
		for (i = 0; i < tagsForChange.length; i++)
		{
			setFontSizeToTags(elId, tagsForChange[i], chngValue); 
		}
	} else if (relFontSizeNew > maxInc) {
		relSizeField.value = maxInc;
	} else if (relFontSizeNew < maxDec) {
		relSizeField.value = maxDec;
	}
}

function setFontSizeToTags(elWithTagId, tag, relSize) {
    if ($("#" + elWithTagId + " " + tag).css("font-size") != undefined) { 
	    var oldFontSize = parseInt($("#" + elWithTagId + " " + tag).css("font-size").replace("px", ""));
	    var newFontSize = Math.round(oldFontSize + (oldFontSize * relSize / 10)) + 'px';
	    $("#" + elWithTagId + " " + tag).css("font-size", newFontSize);
    }
}