非活性按钮
<html><head><title>Login</title><script type="text/javascript" src="show.js"></script></head><body><table><tr><td>用户名：</td><td><input type="text" name="userId" id="userId" style="width: 150px" maxlength="9"/></td></tr><tr><td>密 码：</td><td><input type="password" name="password" style="width: 150px;" size="20" id="password" onkeyup="javascript:show()"/></td></tr><tr><td colspan="2" align="center"><input type="button" name="submit" style="width: 50px; height: 25" value="登陆" id="submit" disabled /></td></tr></table></body></html>
show.js
function show(){var userId = document.getElementById("userId").value;var password = document.getElementById("password").value;if(userId =="" || password ==""|| userId ==null || password ==null){document.getElementById("submit").disabled=true;}else{document.getElementById("submit").disabled=false;}}