console 命令行工具 X clear

console

function check()
{
document.getElementById("myCheck").checked=true
}

function uncheck()
{
document.getElementById("myCheck").checked=false
}

<form> 
  <input type="checkbox" id="myCheck"> 
  <input type="button" onclick="check()" value="选定复选框"> 
  <input type="button" onclick="uncheck()" value="取消选定复选框"> 
 </form>