javascript - Simple Modal isn't working

Question

I'm trying to create a modal with an iframe but the code isn't working. Nothing happens.

I've already put an alert message to see if the function is being called and it is, but the modal isn't created.

Here's my JavaScript code:

function iframe(src){
    alert("Message");
    $.modal('<iframe src="' + src + '" height="450" width="830" style="border:0">', {
        closeHTML: "",
        containerCss: {
            backgroundColor: "#fff", 
            borderColor: "#fff", 
            height: 450, 
            padding: 0, 
            width: 830
        },
        overlayClose:true
    });
}

I've tried to include a file named jquery.simplemodal-1.4.3.js and jquery.simplemodal-1.4.3.min.js but it's still not working.