You can do somthing like this too:
string job = TextBox1.Text;
string query = String.Format("select * from listofjobs where jobs like '%{0}'", job);
SqlCommand command = new SqlCommand(query, conn);
Where the value in variable "job"is assigned to the index {0} in the string "query".
But Prasad_Kulkarni answer your question, mine is just a sugestion.