Blank text field populates on selecting specific value in picklist

Question

Scenario: Project state is the dependent picklist on the country picklist, for Countries which do not have states/have some other state which is not listed in the state picklist, user selects "Other" from the state picklist. Once they select "Other", blank text field should be populated in which the user can enter the name of the state.

Also Project state and Project country is being mapped from Lead to Accounts and opportunities on conversion, hence whatever value entered in the text field, should be mapped to the project state field in the accounts and opportunities

Answer 1

<apex:selectList value="{!country}" reRender="txtOtherCountry">
</apex:selectList>
<apex:inputText value="{!otherCountry}" id="txtOtherCountry" rendered="{!if(country ='other',true,false)}"/>