<body tag deleted!

I've got a HTML that contains a body tag very long:

<body BGCOLOR="#FFFFFF" TEXT="#000000" VLINK="#990000" ALINK="#CC9900" LINK="#003399" onLoad="MM_preloadImages('common/menu_institutes1_f2.gif','#947159853429');MM_preloadImages('common/menu_institutes1_f3.gif','#947159853430');MM_preloadImages('common/menu_institutes2_f2.gif','#947159853431');MM_preloadImages('common/menu_institutes2_f3.gif','#947159853432');MM_preloadImages('common/menu_institutes3_f2.gif','#947159853433');MM_preloadImages('common/menu_institutes3_f3.gif','#947159853434');MM_preloadImages('common/menu_institutes4_f2.gif','#947159853435');MM_preloadImages('common/menu_institutes4_f3.gif','#947159853436');MM_preloadImages('common/freccia_top_f2.gif','#947511352300');">

When I apply tidy to this, the tag is deleted. Why?
I'm using the following options:
-asxml -wrap 0 -m filename.htm
-------------------------------------------
Dr. Elisabetta D'Alessandro
Reggiani S.p.A. EDivision
Via Tonale, 133   21100 Varese -Italy-
tel: +39332 338270
fax: +39332 331539
internet: www.reggiani.it

Received on Friday, 9 February 2001 05:19:11 UTC