操作符，操作类型不匹配

倒数第二句出现问题
txtxz=val(thisform.txtxz.value)
txtygz=val(thisform.txtygz.value)
txtcqr=val(thisform.txtcqr.value)
thisform.txtyfhj.enabled=.t.
thisform.txtkkhj.enabled=.t.
thisform.txtsfhj.enabled=.t.
thisform.txtxz.enabled=.t.
thisform.txtxz.value=txtygz/26 * txtcqr
thisform.txtsfhj.value=thisform.txtxz.value+thisform.txtjbgz.value+thisform.txttlj.value+thisform.txthsbt.value+thisform.txtzwbt.value+thisform.txtxlbt.value+thisform.txtqqj.value+thisform.txtqtjl.value
thisform.txtkkhj.value=thisform.txtwgkk.value+thisform.txthskk.value+thisform.txtgrsds.value