Multiselect box Validation

Hi, we have a BIG problem trying to validate multiselect box fields with client suitescripts in IE6 & IE7. I tried two codes,

Field Change Funtion:

function onChangeFunc(type, name){
    if (name='custentity_partners'){
var multi = nlapiGetFieldValue('custentity_partners');
if (multi && multi.length > 6){
      alert('Warning: You can only select 6 partners');
      nlapiSetFieldValue('custentity_partners',multi.slice(0,multi.length -1),false);
} 
     }
}
    
Field Validate Function:

function onValidateFunc(type,name){
if (name='custentity_partners'){
  var multi = nlapiGetFieldValue('custentity_partners');
  if (multi && multi.length > 6){
   alert('Warning: You can only select 6 partners');
   return false;
  } 
}
return true
}


IE send an alert every time the mouse moves after the condition is reached at once.