Someone

strTextChangedEnter = ((TextBox)sender).Text;
			((TextBox)sender).Font = new Font(this.Font.Name, 10, FontStyle.Bold);
			((TextBox)sender).BackColor = Color.FromArgb(237, 240, 255);
			// light green -> Color.FromArgb(237, 255, 237)
			//light Gray -> Color.FromArgb(244, 244, 244);   
			//light Blue -> Color.FromArgb(236, 240, 255); 
			// light Yellow System.Drawing.SystemColors.Info;
			if (((TextBox)sender).ForeColor != Color.Red)
				((TextBox)sender).ForeColor = System.Drawing.SystemColors.ControlText;
			SendKeys.Send("{RIGHT}");		



strTextChangedLeave = ((TextBox)sender).Text;
			if (strTextChangedEnter != strTextChangedLeave )
			{
				((TextBox)sender).BackColor = System.Drawing.SystemColors.Window;
				((TextBox)sender).Font = new Font(this.Font.Name, 10, FontStyle.Bold);
				if (((TextBox)sender).ForeColor != Color.Red)
					((TextBox)sender).ForeColor = Color.Red;				
			}
			else
			{
				((TextBox)sender).BackColor = System.Drawing.SystemColors.Window;
				if (((TextBox)sender).ForeColor != Color.Red)
				{
					((TextBox)sender).ForeColor = System.Drawing.SystemColors.ControlText;
					((TextBox)sender).Font = new Font(this.Font.Name, 9, FontStyle.Regular);
				}
				else
					((TextBox)sender).Font = new Font(this.Font.Name, 10, FontStyle.Bold);				
			}
			SendKeys.Send("{RIGHT}");