<span style="font-size:14px"> function check(){
var oText = document.getElementById("in").value;
alert(oText);
if(oText =="false"){
return false;
}
else {
return true;}
}</span>

<span style="font-size:14px"> <form action="table1.html" onSubmit="return check();">
<div><input type="text" id="in" /><input type="submit" value="提交" /></div>
</form></span>