function checkEntries() {
    var retval = true;
    if($F('txtName') == '' || $F('txtName') == ' ') 
    {
        $('lblName').innerHTML = 'Required';
        retval = false;
    }
    if($F('txtSurname') == '' || $F('txtSurname') == ' ') 
    {
        $('lblSurname').innerHTML = 'Required';
        retval = false;
    }
    if($F('txtEmail') == '' || $F('txtEmail') == ' ')
    {
        $('lblEmail').innerHTML = 'Required';
        retval = false;
    }
    else if(!checkEmail($F('txtEmail')))
    {
        $('lblEmail').innerHTML = 'Not Valid';
        retval = false; 
    }
    
    if($F('txtMessage') == '' || $F('txtMessage') == ' ')
    {
        $('lblMessage').innerHTML = 'Required';
        retval = false;
    }
    else if (!CheckPalabras($F('txtMessage')))
    {
        retval = false;
    }
    
    if(retval==true){
        show('divCargando');
    }    
    return retval; 
}