Try
Code:
<html>
<head>
<script type="text/javascript">
function nice() {
var inps=document.getElementsById('box');
for(var i=0;i<inps.length-1;i++)
{
inps[i].onblur=nice();
{
if(inps.value.indexOf('/')!=-1 && (inps.value.length>1))
{
alert('Answers should either be number or slash only!nNo Combination Please.');
inps.select();
}
}
}
}
</script>
</head>
<body onLoad="cool();">
<p>Please enter your answer or type ( / ) if you don't know the answer.<br>
Your answer may not contain both numbers and ( / ) sign.<br><br>
34 + 54 = <input type=text size="6"></p>
<p>123 + 76 = <input type=text size="6" name="T1" id="box></p>
<input type=submit value="Check Answer!">
</body>
</html>
Your code seems to be a bit quirky. Like this line for example something looks wrong.
inps[i].onblur=nice();