var range = 100; /* The script gets random number between 0 and 'range' */
var elForZero = 'cesurWrapper'; /* ID of element for theNumber == 0 */
var elForOne = 'cesurWrapper'; /* ID of element for theNumber == 1 */

function randValue() {
    //get a random no upto maxVal and round it to two decimal place
    var theNumber = (Math.random() * parseInt(range)).toFixed(0);

    if (theNumber <= 40)
        document.getElementById(elForZero).style.display = 'block';
	else  
	    document.getElementById(elForOne).style.display = 'block'; 
}