javascript - Rounding this result -

this question has answer here:

• how round number in javascript? 8 answers

i need rounding result , put rounded result 'tb3'.

example:

• 2.1565 -> 2
• 2.9855 -> 3

 <script type="text/javascript"> function sum(){         document.getelementbyid('tb3').value = (((parseint(document.getelementbyid('tb1').value) + (parseint(document.getelementbyid('tb2').value) * 5000))*0.0000083) + 2.9167);} </script>  <input type="text" id="tb1" size="30" onkeyup="sum()" value="0"/> + <input type="text" id="tb2" size="30" onkeyup="sum()" value="0"/> = <input type="text" id="tb3" size="30" value="0" /> 

document.write((2.1565).tofixed());  // output 2 document.write((2.9855).tofixed());  // output 3 

for more info can proceed docs - dev docs @ mozilla