How to embed DataGridView in dll

I want to create a dll with following function, but when i compile i face error,

Error 1 The type or namespace name 'Windows' does not exist in the namespace 'System' (are you missing an assembly reference ) D:\ClassLibrary1\Class1.cs 9 48 ClassLibrary1

How to solve this problem, is there any alternative method solve this problem.

public void fillDataGrid(System.Windows.Forms.DataGridView DataGridName, string DataMemeberName, string Query, System.Data.SqlClient.SqlConnection ConnectionToDatabase, System.Windows.Forms.Form frm)

if (ConnectionToDatabase != null)

System.Data.DataSet ds = new System.Data.DataSet();

System.Data.SqlClient.SqlDataAdapter ad = new System.Data.SqlClient.SqlDataAdapter(Query, ConnectionToDatabase);

ad = null;

ds = null;