使用jQuery延迟加载js文件

//异步加载js文件并调用函数
function delayCall(calledFunction, funcParams, jsUrl)
{
    if (eval('typeof '+calledFunction) == 'function') {
        eval(calledFunction+'(funcParams)');
    } else {
        jQuery.ajax({
            type: 'GET',
            url: jsUrl,
            data: {},
            dataType: 'script',
            cache: true,
            async: true,
            success: function () {
                eval(calledFunction+'(funcParams)');
            }
        });
    }
}

//同步加载js文件
function syncLoad(checkFunction, jsUrl)
{
    if (eval('typeof '+checkFunction) != 'function') {
        jQuery.ajax({
            type: 'GET',
            url: jsUrl,
            data: {},
            dataType: 'script',
            cache: true,
            async: false,
        });
    }
}