var example_inp = new Array(new Array('1', '1', '2', '2', '2', '3'), new Array('', '7', '8', '', '17', '19'),
new Array('', '1', '3', '', '1', '2'), new Array('', '2', '6', '', '1', '3'));

// decimal, percent

var i = Math.floor(Math.random() * example_inp.length);

function example(){
	var form = document.getElementById('calcForm')
	
	leftWhole = document.getElementById('left_whole')
	leftNumer = document.getElementById('left_numer')
	leftDenom = document.getElementById('left_denom')
	rightWhole = document.getElementById('left_whole')
	rightNumer = document.getElementById('right_numer')
	rightDenom = document.getElementById('right_denom')
	
	leftWhole.value = example_inp[i][0];
	leftNumer.value = example_inp[i][1];
	leftDenom.value = example_inp[i][2];
	rightWhole.value = example_inp[i][3];
	rightNumer.value = example_inp[i][4];
	rightDenom.value = example_inp[i][5];
	
	
	i += 1;
	if (i >= example_inp.length)
		i = 0;
}