var ans;
var lbMin=document.getElementById('min'); //span
var lbMax=document.getElementById('max'); //span
var txt=document.getElementById('txt'); //input
var rs=document.getElementById('rs'); //span
function newNumber()
{
  ans=Math.ceil(Math.random()*100)
  lbMin.innerHTML='1'
  lbMax.innerHTML='100'
}
function send()
{
  if(txt.value==ans)
  {
    rs.innerHTML='bingo!';
    newNumber();
  }else{
    if(txt.value>ans)
    {
      rs.innerHTML='太大!';
      lbMax.innerHTML=txt.value;
    }else{
      rs.innerHTML='太小!';
      lbMin.innerHTML=txt.value;
    }
  }
  txt.value='';
}
newNumber();