Previous list/record loosing its selection when the next list/record is selected

Hi,

I have two dynamically added list/record which I added through beforeLoad User Event script.  These two fields are dependent on each other.  Based on the selection of first list, the related items should be added to the next list.  The problem which I am facing is, on inserting the values to the next list, the first list loosing the already selected value.  I am not sure why this happens.

My script

var related_items = nlapiGetFieldValue('custrecord_level_1_item');  if(related_items!='')  {  if(name == 'custrecord_level_1_item')//the first list/record  {  .  .  .    nlapiRemoveSelectOption('custpage_level2', null);//removing all items from the second list  nlapiInsertSelectOption('custpage_level2', 'a1', '',true);  for(var i=0 ; i<related_items.length ; i++)  {  if(flag == 0)  nlapiInsertSelectOption('custpage_level2', related_items[i], related_items_text[i],false);//adding corresponding items to the second list  }  }  }      var related_items_3 = nlapiGetFieldValue('custpage_level2');  if(related_items_3 != 'a1')  {  if(name == 'custpage_level2')//second list/record  {  nlapiRemoveSelectOption('custpage_level2', null);  nlapiInsertSelectOption('custpage_level2', 'a2', '',true);  for(var i=0 ; i<retrieved_items.length ; i++)  {  nlapiInsertSelectOption('custpage_level3', retrieved_items[i], items_to_store[i],false);//inserting values to some other list...  }  //THE SELECTION IN THE FIRST LIST GOES HERE  alert("set");  }  }