proc clearSheet t {

	global CellValues CellFormulae curRow Procs

  	set tw [sheetWin $t]
  	set msgw $tw.msg

        foreach i [array names CellValues] {
		if {[info exists Procs($i)]} {
			trace vdelete CellValues($i) w "cellChange $t $i"
			unset Procs($i)
		}
                set CellValues($i) ""
        }

        foreach i [array names CellFormulae] {
                set CellFormulae($i) ""
        }

        foreach i [$t tag row heads] {
                $t tag row {} $i
        }
        foreach i [$t tag cell formula] {
                $t tag cell {} $i
        }
        foreach i [$t tag row error] {
                $t tag cell {} $i
        }
        foreach i [$t tag row separator] {
                $t tag row {} $i
        }

        keySheet $t
        set curRow 1

	setMsg $msgw "Erased Sheet"

}
