String.prototype.trim = function() {return this.replace(/^\s+|\s+$/g,"");}
String.prototype.ltrim = function() {return this.replace(/^\s+/,"");}
String.prototype.rtrim = function() {return this.replace(/\s+$/,"");}
function vazio(obj){
    var v = (obj.value.trim()=="")?true:false;
    msgerro(obj,"*", v);
    return v;
}
function vemail(email){
    var regex = new RegExp(/^[A-Za-z0-9_\-\.]+@[A-Za-z0-9_\-\.]{2,}\.[A-Za-z0-9]{2,}(\.[A-Za-z0-9])?/);
    if (typeof(email)=="string"){return regex.test(email);}
    if (typeof(email)=="object")
        return regex.test(email.value);
    else
        return false;
}
function msgerro(obj,strmsg, exibir){
    var span = obj.parentNode.getElementsByTagName("span")[0];
    
    if (!span){
        span = document.createElement("span");
        obj.parentNode.appendChild(span);
    }    
    
    if(exibir){
        span.style.display="inline";
        span.innerHTML = strmsg;
    }else{
        span.style.display="none";
    }
}