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) { //v4.01
  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);
  if(!x && d.getElementById) x=d.getElementById(n); 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];}
}
function obrigatorios(form_id) {
    for (var i=0, j=document.getElementById(form_id).length; i < j; i++) {
        o = document.getElementById(form_id).elements[i];
        if ((o.getAttribute('obrigatorio') != null) && (o.value.length == 0)) {
            alert('O campo "' + o.getAttribute('legenda') + '" deve ser preenchido');
            o.focus();
            return false;
        }
    }
    return true;
} 

function retiraDefault(campo) {
	if ((campo.value == campo.defaultValue) || (campo.value == ''))
		return false;
	return true;
}
function canSubmit(form) {
	if (! obrigatorios(form))
		return false;

	if (! retiraDefault(document.getElementById(form).login)) {
		alert('Altere o login');
		return false;
	}
	
	if (! retiraDefault(document.getElementById(form).senha)) {
		alert('Altere a senha');
		return false;
	}
}