Validating url with jQuery without the validate-plugin?

Question

I need to validate a url in variable with jQuery, but can\'t use validate-plugin. Is there a simple way to do this?

Answer 1

Thank you very much Meo and Nick, I put both your answers together and it works just great.

if(/^(http|https|ftp):\/\/[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?$/i.test($("#url").val())){
    alert("valid URL");
} else {
    alert("invalid URL");
}