function validar(formulario) {

if( formulario.Category.value==-1 )
{
alert("You have to select a category");
return false;
}
if( validarformato(formulario.title,"no",0,6)==false )
{
alert("You have to fill up the title.");
return false;
}
if( validarformato(formulario.Description,"no",0,6)==false )
{
alert("You have to fill up the description.");
return false;
}
if( validarformato(formulario.recuadro,"no",0,8)==false )
{
 return false;
}  
 
if (formulario.Aceptar.checked == false)
{
alert("You have to accept the terms and conditions of using this website")
return false;
}
document.formulario.submit();

}

 function validarformato(variable,cadena,mirar,longitud) 
 {
 cadena1 = variable.name;
  cadena1=cadena1.replace("_" ," ");
    cadena1=cadena1.replace("_" ," ");
   cadena1=cadena1.replace("recuadro" ,"box below");

 if (variable.value.length == 0 && mirar == 1)
  {
  return true;
  }
 if (variable.value.length < longitud) {

    alert("The " +  cadena1 + " requires more than " + longitud + " letters");
    variable.focus();
    return (false);
  }
   
 if (cadena == "si"){
  var checkOK = "ABCDEFGHIJKLMNÑOPQRSTUVWXYZÁÉÍÓÚ.," + "abcdefghijklmnñopqrstuvwxyzáéíóú ";
  var checkStr = variable.value;
  var allValid = true; 
  for (i = 0; i < checkStr.length; i++) {
    ch = checkStr.charAt(i); 
    for (j = 0; j < checkOK.length; j++)
      if (ch == checkOK.charAt(j))
        break;
    if (j == checkOK.length) { 
      allValid = false; 
      break; 
    }
  }
  if (!allValid) { 
    alert("You only have to write letters in this field "+cadena1); 
    variable.focus(); 
    return (false); 
  }}
   if (cadena == "numerico"){
  var checkOK = "0123456789- " ;
  var checkStr = variable.value;
  var allValid = true; 
  for (i = 0; i < checkStr.length; i++) {
    ch = checkStr.charAt(i); 
    for (j = 0; j < checkOK.length; j++)
      if (ch == checkOK.charAt(j))
        break;
    if (j == checkOK.length) { 
      allValid = false; 
      break; 
    }
  }
  if (!allValid) { 
    alert("You only have to write numbers in this field "+cadena1); 
    variable.focus(); 
    return (false); 
  }}  

 return true
 }