asp.net 表单验证新思路

public static int IntRound(int Max) 
{ 
Random r = new Random(); 
int i = r.Next(0, Max); 
r = null; 
return i; 
} 

int i=IntRound(8); 
if (Request.Form["txt" + i] != "") 
{ 
} 

if (Request.Form[i] != "") 
{ 
}