Hi Virgilio
As Mr. Vladimir mentioned the link, that is a best example. Any how you can use timer to make the text blinking.
Click timer and put it on your form and in the properties of timer write the following code in the timer event. And change the value of interval to 500

Example, If the caption of the form is "My Form"

if thisform.caption="My Form"
  thisform.caption=" "
else
  thisform.caption="My Form"
endif

If you have label named "Label1" and its caption is "Label1"
then the codes will like

if thisform.label1.caption="Label1"
  thisform.caption=" "
else
  thisform.label1.caption="Label1"
endif

Hope it will work

Zaheer