function clsOver(val) { 
	if(val != '') {					
		var vdoc = document.getElementById('headerimg');
		if(val == 'mnhome') vdoc.style.background = 'url(images/header1.jpg)';
		else if(val == 'mndespre') vdoc.style.background = 'url(images/header2.jpg)';
		else if(val == 'mnserv') vdoc.style.background = 'url(images/header3.jpg)';
		else if(val == 'mnrez') vdoc.style.background = 'url(images/header4.jpg)';
		else if(val == 'mngal') vdoc.style.background = 'url(images/header5.jpg)';
		else if(val == 'mncontact') vdoc.style.background = 'url(images/header6.jpg)';		
	}
}