var fadingOut = 100
var fadingIn = 0
var interval
var interval2


function contentFade(number, data){
	
	// highlighting the the current button that is open
	
	var currentID = data.id
	
	document.getElementById('btnGallery').className = 'btnGallery'
	document.getElementById('btnAbout').className = 'btnAbout'
	document.getElementById('btnPrices').className = 'btnPrices'
	document.getElementById('btnContact').className = 'btnContact'
	
	document.getElementById(data.id).className = currentID + 'Selected'
	
	// checking to see if anything is open
	for(var i=1; i<=4; i++){
		var element = document.getElementById('content-' + i)
		if(element.style.display == ''){
			if(number == i){return false} // checking if the window was already opened
			interval = setInterval('fadeOut(' + i + ',' + number + ')', 1)
		}
	}
}

function fadeOut(data, data2){

	var element = document.getElementById('content-' + data)
	var element2 = document.getElementById('content-' + data2)
	
	if(fadingOut == 0){
		element.style.display = 'none' // hiding window
		fadingOut = 100
		clearInterval(interval)
		interval2 = setInterval('fadeIn(' + data2 + ')', 5)
	}
	else{
		fadingOut = fadingOut - 10
		element.style.filter = 'alpha(opacity=' + fadingOut + ')'
		element.style.opacity = fadingOut / 100;
	}
}

function fadeIn(data){
	
	var element = document.getElementById('content-' + data)
	
	if(fadingIn == 100){
		fadingIn = 0
		clearInterval(interval2)
		return false
	}
	else{
		element.style.filter = 'alpha(opacity=' + fadingIn + ')'
		element.style.opacity = fadingIn / 100;
		element.style.display = '' // showing window
		fadingIn = fadingIn + 10
	}
}