Javascript round to given precision
Use Math.round(num * 100) / 100
Edit: to ensure things like 1.005 round correctly, we use
Math.round((num + Number.EPSILON) * 100) / 100
or use string function toFixed
If the value is a text type:
parseFloat("123.456").toFixed(2);
If the value is a number:
var numb = 123.23454;
numb = numb.toFixed(2);