Undo In Javascrip

[Hemant Mane]

Hi Friends, I am developing a web site In one web page there are 2 dropdownlist and containg save data for example select1 1)abc 2)xyz 3)pqr and for Select2 1)abc 2)xyz 3)pqr If user select abc in select1 and then he select same abc in select2 a error messege through to user that You choose Abc in select1 so please select diffrent item no this time i can give index no to select2 but i want the last value of select2 suppose selet2 has pqr selected and then he try to select abc then after error he atomatacally select the last value i.e. pqr In short Undo in javascript for dropdownlist Thank You In Advance