如何得到radio得值?
<form name="form1" method="post" action="">
<input name="RadioGroup1" type="radio" value="1" checked >
open
<input type="radio" name="RadioGroup1" value="0" >
close
<input type="submit" name="Submit" value="Submit" onClick="alert(RadioGroup1.value);">
</form>
我这样写的,为什么点button事后的道德不是"0"或"1",而是“undefined”..
是什么地方错了?