How can we create Dependent Picklist(Pictlist values based on another picklist)

Hi all,

Can any body explian me how can we create Picklist values based on another picklist values.
For ex:: Country is Picklist value(It contains the list of all countrys)
            State is another picklist value(it will display the states related to the Country which we have selected)

Can any one explains how can we achive the above functionality in outsystems..