Can u give more details about what you want exactly.
what i understand from your question is as :
1) you have a grid or something in your apps and that you populate using a query like
'SELECT * FROM CityMaster'
2) Now you need to create a text box for a search like if any one enter the A and hit the search button then you want to display and city name in grid stucture or something where city name start from a
If is this a scenarion what i am talking about then you need to fire the below query under the search command.
Select * from CityMaster Where CityName Like '" & TextBox1.Text & "%'"