How to get ordered values from ListSelect if setMultiSelect is true

Hi ,

       In my project, i am using ListSelect component. I am using IndexedContainer and i have set items on ListSelect. I also set multiSelect(true). while selecting multiple items from ListSelect, it has return as Set(Collection) values. It doesnt maintain order.  But, i need to get values from ListSelect as like my selection order. Please help me to implement the same.