Textbox validation

Hi Everyone, I want to validate the textbox contain only floating point values which always in "xxx.xx" formate 3 digit and after "." two digit. i try this Global $iicd1 = GUICtrlCreateInput("", 208, 310, 60, 20,$ES_Number) GUICtrlSetLimit(-1, 6) but didn't get "." any one please look on this and do the needful thank in advance