// JavaScript Document

function resizeText(multiplier) {
	// Increase or decrease text size in a page where CSS defines font sizes in em
	var nMinSize = 0.6;
	var nMaxSize = 1.4;
	var nIncrement = 0.1;
	
	if (document.body.style.fontSize == "") {
		// First call to function
		if (multiplier > 0) { document.body.style.fontSize = "1.1em"; }
		if (multiplier == 0) { document.body.style.fontSize = "1em"; }
		if (multiplier < 0) { document.body.style.fontSize = "0.9em"; }	 
 	} else {
		if (multiplier == 0) {
			document.body.style.fontSize = "1.0em";
			document.getElementById('decrease_text').style.visibility = 'visible';
			document.getElementById('increase_text').style.visibility = 'visible';
		} else {
			if (((parseFloat(document.body.style.fontSize) > nMinSize) && (parseFloat(document.body.style.fontSize) < nMaxSize)) ||
			 ((parseFloat(document.body.style.fontSize) <= nMinSize) && (multiplier > 0)) ||
			 ((parseFloat(document.body.style.fontSize) >= nMaxSize) && (multiplier < 0))) {
 				document.body.style.fontSize = parseFloat(document.body.style.fontSize) + (multiplier * nIncrement) + "em";
				document.getElementById('decrease_text').style.visibility = 'visible';
				document.getElementById('increase_text').style.visibility = 'visible';
			} else {
				if (multiplier > 0) {
					alert("Maximum text size reached.");
					document.getElementById('increase_text').style.visibility = 'hidden'; 
				}
				if (multiplier < 0) {
					alert("Minimum text size reached.");
					document.getElementById('decrease_text').style.visibility = 'hidden'; 
				}
			}
		}
	}
}