Ill be using the bar graph to display the reception of the sm5100b sms module.
As I recall, an sm4100b sms module receives text messages sent from a cell phone. You want to display the text message as a bar graph?
Some information on what GLCD (and library) you have would be useful.
Most GLCDs have some mechanism for drawing filled or empty rectangles. You want to draw two rectangles - one filled, one empty. The size/placement of the upper, left corner of the pair, and the lower, right corner of the pair is fixed. The other two corners depend on ? (how many messages, how much text in the message, how long ago the message was sent, something else entirely).