求助啊!!!!关于数据连接的问题

string title = newsTitle.Text;
        string style = newsStyle.SelectedItem.Text;
        string content = newsContent.Text;

        string strCon = "server=localhost;database=news;uid=sa";
        SqlConnection con = new SqlConnection(strCon);
   
        string sql = "insert into new('" + title + "','" + style + "','" + content + "')";
        con.Open();
        SqlCommand com = new SqlCommand(sql, con);
      
         com.ExecuteNonQuery();
        con.Close();

这段代码运行的时候 为什么会出现下面的错误啊?
c:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\WebSite6\发布新闻.aspx.cs(33,9): error CS0246: 找不到类型或命名空间名称“SqlConnection”(是否缺少 using 指令或程序集引用?)
c:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\WebSite6\发布新闻.aspx.cs(33,33): error CS0246: 找不到类型或命名空间名称“SqlConnection”(是否缺少 using 指令或程序集引用?)
c:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\WebSite6\发布新闻.aspx.cs(37,9): error CS0246: 找不到类型或命名空间名称“SqlCommand”(是否缺少 using 指令或程序集引用?)
c:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\WebSite6\发布新闻.aspx.cs(37,30): error CS0246: 找不到类型或命名空间名称“SqlCommand”(是否缺少 using 指令或程序集引用?)