syntax hignlighting

This may help:

Window = CreateWindow("HTML Editor", 100, 100, 400, 300, 0)
Panel = CreatePanel(0, 0, ClientWidth(Window), ClientHeight(Window), Window)

TextArea = CreateTextArea(0, 0, ClientWidth(Panel), ClientHeight(Panel), Panel)

Timer = CreateTimer(100) ;100 ms
AreaText$ = "" ;TextArea Text

count = False
countNum% = 1
Tag$ = ""

Repeat

Select WaitEvent()
	Case $803
	End
	
	Case $4001 ; Tick
	Select EventSource()
		Case Timer
		
		tmp$ = TextAreaText$(TextArea) ; Grab Text
		If tmp$ <> AreaText$ Then ; User has entered a character
			tmp2$ = Right(tmp$, Len(tmp$) - Len(AreaText$)) ; Isolate new from old entry
			If count = False ;If your not currently getting the HTML tag
				If Instr(Lower(tmp2$), "<", 1) Then count = True ;If the character entered is <, start getting tag 
			Else If count = True ;Your are getting the HTML tag
				If Instr(Lower(tmp2$), ">", 1) ;Is it the end tag?
					countNum = countNum + 1 ;Increase the characters
					count = False ;Stop counting
					z = CheckTag(Tag$) ;Is it an HTML tag?
					If z = True ;It is a HTML tag
						FormatTextAreaText(TextArea, 255, 0, 0, 0, TextAreaLen(TextArea) - countNum, countNum) ;Higlight the Tag
					End If
					Tag$ = "" ;Reset Tag
					countNum = 1 ;num  of characters back to one
				Else ;It's not the end tag
					Tag$ = Tag$ + tmp2$  ;Add the chracter to the Tag
					countNum = countNum + 1 ;Add 1 to the num of chars
				End If
			End If			
			AreaText$ = tmp$
		EndIf
		
	End Select

End Select

Forever

Function CheckTag(tagToCheck$)

	tagToCheck$ = Upper(tagToCheck$)
	
	a = ReadFile("files/tags.mltg")
		
	Repeat
	
		b$ = ReadLine(a)
		c$ = "/" + b$ ;To see if it is an end tag
		
		If b$ = tagToCheck$
			Return True
		Else If c$ = tagToCheck$
			Return True
		End If
					
	Until Eof(a)
	
	
	
	Return False
	
End Function

in the html file i put all the html tags i could find. There are problems with this though with backspaces. If you put <htmlk and backspace, it wont work when you put the > as the tag would be "htmlk". I hope that makes sense!