How Do You Build A Dynamic WHERE Statement?

I have 5 drop down lists and 1 text box, and I need to build the WHERE portion of my SELECT statment (stored procedure). the drop down lists are named client, ptype, apptdate, inspdate, state, and the textbox is named text. they all need to be this=something AND that=another AND...AND text LIKE mytext.

How would I go about building this efficiently?

Would I Declare a bit value in the sp called WhereSet = 0

IF @client IS NOT NULL
     IF @WhereSet = 0
          SET @Where = 'WHERE ClientID=@client'
          SET @SetWhere = 1
    ELSE
          SET @Where = @Where + ' AND CleintID=@client'
    .
    .
    ....

Or would this be a lot easier using adhoc SQL instead of a Stored Procedure?

(note: I am using a SQL DataSource)

Please help, I am going bald from pulling my hair our...