text box เวลาเราพิมพ์ค่าเข้าไปแล้ว ให้แปลงเป็นตัวพิมพ์ใหญ่ทั้งหมด

dim ToupStr as string 
ToupStr =textbox1.text
ToupStr.Toupper() 

//Version JavaScript แบบ server side initialized ค่ะ

private void InitJavaScriptFromServerSide()
{
   System.Text.StringBuilder MyStrStream= new System.Text.StringBuilder() ;
   MyStrStream.AppendLine("<script type=\"text/javascript\">") ; 
   MyStrStream.AppendLine("function FnToUpper(arg)") ; 
   MyStrStream.AppendLine("{") ; 
   MyStrStream.AppendLine("  arg.value=arg.value.toUpperCase().replace(/([^0-9A-Z])/g,\"\");") ; 
   MyStrStream.AppendLine("}") ; 
   MyStrStream.AppendLine("</script>") ; 
   MyStrStream.AppendLine("") ; 
   
   Page.RegisterClientScriptBlock("JavaScriptExtensionBlock" ,MyStrStream.ToString());
}

private void SetTextBoxAutoUpperCase(System.Web.UI.WebControls.TextBox varTextBox )
{
	varTextBox.Attribute.Add("onblur" ,"FnToUpper(this);");
	varTextBox.Attribute.Add("onkeydown" ,"FnToUpper(this);");
	varTextBox.Attribute.Add("onkeyup" ,"FnToUpper(this);");
	varTextBox.Attribute.Add("onclick" ,"FnToUpper(this);");
} 

// ตอนใช้งาน
.....
protected void Page_Load(object sender, EventArgs e)
{
  if(!isPostBack)
  {
  	InitJavaScriptFromServerSide() ;
  	
  	SetTextBoxAutoUpperCase(TextBoxDescription) ;
  }
}

Private Sub textbox1_textchange()
textbox1.text = textbox1.text.toupper
sendkeys.send("{END}")
end sub