SOURCE

function writeDocument(variable) {
    document.write(variable + "<br/>");
} 
writeDocument("最大值最小值--------");
writeDocument("最大值"+Math.max(220,15,48,96));
writeDocument("最小值"+Math.min(220,15,48,96));

writeDocument("生成四位随机验证码--------");
function generateVerifyCode(length){
    var strLetterNumber="0123456789ABCDEFGHIJKLMNOPQRST";
    var code="";
    for(var i=0;i<length;++i){
        var randomNumber=Math.floor(Math.random()*strLetterNumber.length);
        code=code+strLetterNumber.charAt(randomNumber);
    }
    return code;

}
writeDocument(generateVerifyCode(4));
writeDocument(generateVerifyCode(5));
writeDocument(generateVerifyCode(6));


writeDocument("生成随机的颜色 rgb(255,255,255)--------");
function getRandomColor(){
    var r = Math.floor(Math.random() * (255 + 1));
    var g = Math.floor(Math.random() * (255 + 1));
    var b = Math.floor(Math.random() * (255 + 1));
    var rgb = "rgb(" + r + "," + g + "," + b + ")";
    return rgb;
    }
     
writeDocument(getRandomColor());