Filter a child picklist in CRM 2011

Question

I'm trying to convert javascript code from CRM 4.0 to CRM 2011. I'm having problems with a picklist filter.

My function is on the onchange of the parent picklist. It works the first time but the second it erase everything from my child picklist.

This is the part where I suppose to reset the picklist

    if(!oSubPicklist.originalPicklistValues)
{
oSubPicklist.originalPicklistValues = oSubPicklist.getOptions();
}
else
{
oSubPicklist.getOptions = oSubPicklist.originalPicklistValues;
oSubPicklist.setOptions = oSubPicklist.originalPicklistValues;
}

And this is the part where i remove all the option not related: oTempArray is an array with the options that i want to keep. If a check the "oSubPicklist.getOptions.length" the value is the same that my original picklist.

    for (var i=oSubPicklist.getOptions.length; i >= 0;i--)
    {
        if(oTempArray[i] != true)
        {
    Xrm.Page.getControl("new_product").removeOption(i);
        }
    }

Ideas?

Edit: I solved declaring a global var with the originalPickList in the onLoad event and:

oSubPicklist.clearOptions();
for (var i=0; i< oSubPicklist.originalPicklistValues.length; i++) 
    {
    for (var j=0; j< oDesiredOptions.length; j++)
        {
        if (i == oDesiredOptions[j])
        {oSubPicklist.addOption(oSubPicklist.originalPicklistValues[i]);}
        }
    }

Answer 1

Your code is not very clear to me: May be you could paste all your function code for better understanding but:

1. This is how you get the options from PickList in CRM 2011

   var myOptionSet = Xrm.Page.ui.controls.get("new_product")   //get Control
   var optionsSet = myOptionSet .getAttribute().getOptions();  //get Options
   preferredTimeOptionSet.clearOptions();                    //Clear all options
   
   //Create a new Option
   var opt1 = new Option();
   opt1.text = "one";
   opt1.value = 1;
   
   //Add Option
   myOptionSet.addOption(opt1);
   
   //Remove Option
   myOptionSet.removeOption(1);
   

Good Example here