function CheckField(field,nchars,s)
   {  if(field.value == null || field.value == "" || field.value.length<nchars){ alert("Atención:\rDebe completar correctamente el campo "+field.name.toUpperCase()); field.value="";field.focus();field.select();return false; }
      return true;
   }

   function ValidateForm()
   {  var i,a=ValidateForm.arguments,form=a[0];
	
      for(i=1;i<(a.length);i=i+2) 
      {  if(!CheckField(a[i],a[i+1])) return false; 
      }
      return true;
   }


   function ValidateFormEx()
   {  var i,a=ValidateFormEx.arguments,form=a[0];

      for(i=1;i<(a.length);i=i+2) 
      {  if(!CheckField(a[i],a[i+1])) return false; 
      }
	
      form.submit();

   }