Page.Response.Write("<script>var response;</script>");
Page.RegisterStartupScript("RegisterStartupScript","<script>var RegisterStartupScript;</script>");
Page.RegisterClientScriptBlock("RegisterClientScriptBlock","<script>var RegisterClientScriptBlock;</script>");
Response.Write输出后的位置在源文件的第一行.
RegisterStartupScript输出后的位置会在<form>的下一行(在asp.net自带的脚本和一些隐藏域之下).
RegisterClientScriptBlock输出后的位置会在</form>的上一行.
