asp.net将获取的值传到后台，然后判断再返回到页面上

将文本框的值传递到后台来判断在返回给页面显示。怎么做。。。

protected void btnSubmit_Click(object sender, EventArgs e)
{
string name = txtName.Text;
string phone = txtPhone.Text;
string title = txtTitle.Text;
string content = txtContent.Text;
string date = DateTime.Now.ToString();

    if (content.Length > 255)
    {
        content = content.Substring(0, 255);
    }

    if (name != "" & phone != "" & title != "" & content != "")
    {
        dbConnect dbcon = new dbConnect();
        dbcon.insertLiuyan(name, phone, title, content, date);

        txtName.Text = "";
        txtPhone.Text = "";
        txtTitle.Text = "";
        txtContent.Text = "";
        txtCheckCode.Text = "";
        RegisterClientScriptBlock("insertSuccess", "<script>alert('您的留言已提交成功，敬请期待我们给您的答复！')</script>");
    }

} 
    如果您用的是Web Form，像这样直接用文本框名称.文本框属性就可以了。

protected void Page_Load(object sender, EventArgs e)
{
mobileRedirect();
string keyword = Request.QueryString["keyword"];

    if (keyword == null || keyword.Trim() == "")
    {
        keyword = "#";
    }

使用Request.QueryString[""]方法，引号中是表单的名称。