Like Query Sql

SELECT Lead.LeadId, Lead.Phone, Lead.ReferredBy, Leadcategory.LeadCategoryName, Leadcategory.LeadCategoryId,
                                Lead.FirstName + ' ' + Lead.LastName AS Name,Lead.UserName
                                FROM  Lead INNER JOIN
                                Leadcategory ON Lead.LeadCategoryId = Leadcategory.LeadCategoryId
                                WHERE (Lead.UserName LIKE '%" + clientName + "%')