Slug from title with pure JS

Title filed
<input name="title" type="text" class="form-control" placeholder="Enter title" onload="convertToSlug(this.value)" onkeyup="convertToSlug(this.value)">

Slug field
<input name="slug" type="text" class="form-control" id="slug-text" placeholder="web-developer">

Script
<script>
    function convertToSlug(str) {
        //replace all special characters | symbols with a space
        str = str.replace(/[`~!@#$%^&*()_\-+=\[\]{};:'"\\|\/,.<>?\s]/g, ' ').toLowerCase();

        // trim spaces at start and end of string
        str = str.replace(/^\s+|\s+$/gm, '');

        // replace space with dash/hyphen
        str = str.replace(/\s+/g, '-');

        //return str;
        document.getElementById("slug-text").value = str;
    }
</script>