两个简单问题！

[cqnetboy]

1:
string a = "1001.0200";
请问怎么把他按人民币的格式打印？如1001.02只保留两个小数?

2：
在cs文件里生成一个table

System.Web.UI.WebControls.Table tab_ShopCar
TableRow tr = new TableRow();
TableCell tc1 = new TableCell();
tc1.Width = 59;
//居中对齐------------------------------
tc1.HorizontalAlign = "center";
//--------------------------------------
tr.Cells.Add(tc1);
tab_ShopCar.Rows.Add(tr);
*********************************************************************

//居中对齐------------------------------
tc1.HorizontalAlign = "center";这句报错：c:\inetpub\wwwroot\UsersInfo\ShopCar.aspx.cs(68): 无法将类型“string”隐式转换为“System.Web.UI.WebControls.HorizontalAlign”
请问怎么做啊？
//--------------------------------------

[ahui_net]

string a = "1001.0200";
a = a.Split('.')[0]+"."+a.Split('.')[1].Substring(0,2);
Response.Write(a);

[ahui_net]

tc1.HorizontalAlign = HorizontalAlign.Center;