>I make it to work, thanks again: Do you see any problems here?

No with ControlSource set;
Only a simplified version ( with my style )

LOCAL llError
DO case
CASE EMPTY(m.this.Value)
	local lcText
	lcText = strtran(m.this.text,"AM","")
	lcText = strtran(m.lcText,"PM","")
	lcText = strtran(m.lcText,"M","")

	if !empty(chrtran(m.lcText,"/.:-","    "))
		****************************************
		* I'm not sure that you can  run here
		****************************************
		
		*This.Value=CTOD("^"+STR(YEAR(DATE()),4)+"-"+STR(MONTH(DATE()),2)+"-"+LEFT(This.Text,2))
		=ErrorMsg('Please enter a valid date',0+16,"Error in date entry")
        llError = .t.
	endif

case m.this.value < m.this.dRangeLowBound
	=ErrorMsg('Please enter a correct year',0+16,"Error in date entry")
	llError = .t.
endcase

return IIF(m.llError, m.this.dRangeLowBound, {}) && so it would work for empty dates

>

>*---------------------- Location Section ------------------------
>*   Library: 	Acustomcontrols.vcx
>*   Class: 		Txtdate
>*   Method: 	Rangelow()
>*----------------------- Usage Section --------------------------
>*)  Description:
>*)
>
>*   Scope:      Public
>*   Parameters:
>*$  Usage:
>*$
>*   Returns:
>*--------------------- Maintenance Section ----------------------
>*   Change Log:
>*       CREATED 	04/14/2005 - NN - idea by Fabio Lunardon thread #1003937
>*		MODIFIED
>*----------------------------------------------------------------
>LOCAL llError
>llError = .f.
>do case
>
>case type('this.value') = "D" AND EMPTY(this.Value)
>	if !empty(chrtran(this.text,"/.-",""))
>		*This.Value=CTOD("^"+STR(YEAR(DATE()),4)+"-"+STR(MONTH(DATE()),2)+"-"+LEFT(This.Text,2))
>		=ErrorMsg('Please enter a valid date',0+16,"Error in date entry")
>		llError = .t.
>	endif
>
>case type('this.value') = "T" AND EMPTY(this.Value)
>	local lcText
>	lcText = strtran(this.text,"AM","")
>	lcText = strtran(m.lcText,"PM","")
>	lcText = strtran(m.lcText,"M","")
>
>	if !empty(chrtran(m.lcText,"/.:-",""))
>*This.Value=CTOD("^"+STR(YEAR(DATE()),4)+"-"+STR(MONTH(DATE()),2)+"-"+LEFT(This.Text,2))
>		=ErrorMsg('Please enter a valid date',0+16,"Error in date entry")
>        llError = .t.
>	endif
>
>case this.value < this.dRangeLowBound
>	=ErrorMsg('Please enter a correct year',0+16,"Error in date entry")
>	llError = .t.
>endcase
>
>return IIF(m.llError, this.dRangeLowBound, {}) && so it would work for empty dates
>

>
>>>>>My question is how to trap years less than 1900 in valid of the textbox. It seems like this year is converted to 1900 by VFP... Try to play with form and textbox which is date type.
>>>>
>>>>Can you explain better ?
>>>
>>>Create a test form. Put textbox on a form and set its value to =date(10,15,1965). Now run the form and try to change year to 0000. The "Invalid date" message would appear only when you put 1/1/0000 or any date less than 03/01/0000 (I'm using SET DATE TO American). But when you click on this textbox again you'll see, that the year automatically was converted to 1900 if you put something like 3/2/0000.
>>>
>>>In my date class I want to trap all years less than currrent year - 110 and display a message. Yesterday I tried to implement it, but it didn't work. However, I spent ~ 5 minutes on it because it was at the end of the day. If you have ideas how to achieve my goal, they are more than welcommed, otherwise I'll start playing with it myself.
>>
>>

>>* RangeLow
>>RETURN GOMONTH(DATE(),-110*12) && this is the lowerBound
>>

>>
>>

>>** Class RangeLow
>>IF m.this.Value<m.this.RangeLowBound && ADD THIS PROPERTY
>>   MESSAGEBOX("Error ... blb bls ...")
>>ENDIF
>>RETURN m.this.RangeLowBound
>>