投票最后显示进度条的百分比怎么算

public class voteresult : System.Web.UI.Page
{
protected System.Web.UI.HtmlControls.HtmlTableCell td_vote;
protected System.Web.UI.HtmlControls.HtmlTable tab_result;
private void Page_Load(object sender, System.EventArgs e)// 在此处放置用户代码以初始化页面
{
tab_result=new HtmlTable();
string voteid=Request.Params["voteid"];
string optionid=Request.Params["optionid"];
CommonFunction.SQLConnection scon=new SQLConnection();
System.Data.DataTable dt;
System.Web.UI.HtmlControls.HtmlTableCell tc;
System.Web.UI.HtmlControls.HtmlTableRow tr;
string sql="";
sql="update voteinfo set optioncount=optioncount+1 where voteid="+voteid+" and optionid="+optionid;
scon.OperationRecord(sql);
sql="select optionstr,optioncount from voteinfo where voteid="+voteid;dt=scon.Query(sql);
int i=0;
int length=0;
while(i<dt.Rows.Count)
{
if(length<(int)dt.Rows[i].ItemArray[1])
length=(int)dt.Rows[i].ItemArray[1];
i++;
}
i=0;
td_vote.InnerHtml="<table border=\"1\" cellspacing=\"1\" cellpadding=\"1\" align=\"center\">";
while(i<dt.Rows.Count)
{
td_vote.InnerHtml+="<tr>";
td_vote.InnerHtml+="<td>";
td_vote.InnerHtml+=(string)dt.Rows[i].ItemArray[0];
td_vote.InnerHtml+="</td><td width=\"200\">";
//tc=new HtmlTableCell();
//tr=new HtmlTableRow();
//tc.InnerText=
//tr.Cells.Add(tc);
//tc=new HtmlTableCell();
td_vote.InnerHtml+="<img src=\"images/long.gif\" width=\""+(((int)dt.Rows[i].ItemArray[1]*100/length)*2)+"\" height=\"9\">";
//tc.InnerHtml=
//tr.Cells.Add(tc);
td_vote.InnerHtml+="</td><td>";
td_vote.InnerHtml+=((int)dt.Rows[i].ItemArray[1]).ToString();;
//tc=new HtmlTableCell();
//tc.InnerText=
td_vote.InnerHtml+="</td></tr>";
i++;
}
td_vote.InnerHtml+="</table>";
}