function validar(){
	var nome = document.contato.nome.value;
	var email = document.contato.mensagem.value;
	var mensagem = document.contato.mensagem.value;
	
	if(!nome || !email || !mensagem){
		document.contato.submit.disabled=true;
	}else{
		document.contato.submit.disabled=false;
	}
}

function MM_swapImgRestore() { //v3.0
    var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
    }

    function MM_preloadImages() { //v3.0
    var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
    }

    function MM_findObj(n, d) { //v3.0
    var p,i,x; if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
    if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
    for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document); return x;
    }

    function MM_swapImage() { //v3.0
    var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
    if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}  
    
 /* menu drop down */
    
    var timeout	= 500;
    var closetimer	= 0;
    var ddmenuitem	= 0;

    // open hidden layer
    function mopen(id)
    {	
    	// cancel close timer
    	mcancelclosetime();

    	// close old layer
    	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';

    	// get new layer and show it
    	ddmenuitem = document.getElementById(id);
    	ddmenuitem.style.visibility = 'visible';

    }
    // close showed layer
    function mclose()
    {
    	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
    }

    // go close timer
    function mclosetime()
    {
    	closetimer = window.setTimeout(mclose, timeout);
    }

    // cancel close timer
    function mcancelclosetime()
    {
    	if(closetimer)
    	{
    		window.clearTimeout(closetimer);
    		closetimer = null;
    	}
    }

    // close layer when click-out
    document.onclick = mclose;