Mine

using System;

public class Test
{
	public static void Main()
	{
		int divisor = 2;
		DateTime startTime = DateTime.Now;
		
		for( int cur = 0; cur < 100000; cur++ )
		{
			while( (divisor^2) < cur )
			{
				if( cur % divisor == 0 )
					break;
			}
			
			divisor += 1;
		}
		
		DateTime stopTime = DateTime.Now;
		
		TimeSpan duration = stopTime - startTime;
		Console.WriteLine(duration);
		
		return;
	}
}

/*
Administrator@Amnesiac>mcs test.cs
Administrator@Amnesiac>./test.exe
00:00:00.0163000
Administrator@Amnesiac>./test.exe
00:00:00.0208170
Administrator@Amnesiac>./test.exe
00:00:00.0160400
Administrator@Amnesiac>./test.exe
00:00:00.0100380
Administrator@Amnesiac>./test.exe
00:00:00.0153370
Administrator@Amnesiac>./test.exe
00:00:00.0169840
Administrator@Amnesiac>./test.exe
00:00:00.0141330
Administrator@Amnesiac>./test.exe
00:00:00.0138640
Administrator@Amnesiac>./test.exe
00:00:00.0181650
Administrator@Amnesiac>./test.exe
00:00:00.0112760
*/