var currentVendorBlockId = 0;
var maxVendorBlockId = 0;

while ( document.getElementById( 'vendorsGroup' + (maxVendorBlockId + 1) )) {
	maxVendorBlockId = maxVendorBlockId + 1;
}
function showVendorsBlock( id ){
	var newVendorsBlock = document.getElementById( 'vendorsGroup' + id );
	var prevVendorsBlock = document.getElementById( 'vendorsGroup' + currentVendorBlockId );
	if( newVendorsBlock ){
		if( prevVendorsBlock ){
			prevVendorsBlock.style.display = 'none';
			setOpacityRec( prevVendorsBlock , 10 );
		}
		setOpacityRec( newVendorsBlock , 0 );
		newVendorsBlock.style.display = '';
		currentVendorBlockId = id;
		setTimeout( "raiseVendor(0)" , 20 );
	}
	
}

function raiseVendor( opacity ){
	setOpacityRec( document.getElementById( 'vendorsGroup' + currentVendorBlockId ) , opacity );
	if( opacity < 10 ){
		opacity = opacity + 1;
		setTimeout( "raiseVendor("+ opacity + ")" , 20 );
	}
}

function prevVendorsGroup(){
	if(currentVendorBlockId > 0 ){
		showVendorsBlock( currentVendorBlockId-1 );
	} else {
		showVendorsBlock( maxVendorBlockId );
	}
}
function nextVendorsGroup(){
	if(currentVendorBlockId < maxVendorBlockId ){
		showVendorsBlock( currentVendorBlockId+1 );
	} else {
		showVendorsBlock( 0 );
	}
	
}

function setOpacityRec( obj , opacity ){
	if( obj.style ){
	setOpacity( obj , opacity );
	var i;
	for(i = 0 ; i < obj.childNodes.length ; i++ ){
		setOpacityRec( obj.childNodes[i] , opacity )
	}
	}
}

showVendorsBlock( 0 );