download file with url component

HTML

<button id="download">
download file
</button>

JavaScript

/* Helper function */
function download_file(fileURL, fileName) {
alert(21)
    // for non-IE
    if (!window.ActiveXObject) {
        var save = document.createElement('a');
        save.href = 'https://www.antennahouse.com/XSLsample/pdf/sample-link_1.pdf';
        save.target = '_blank';
        var filename = fileURL.substring(fileURL.lastIndexOf('/')+1);
        save.download = fileName || filename;
	       if ( navigator.userAgent.toLowerCase().match(/(ipad|iphone|safari)/) && navigator.userAgent.search("Chrome") < 0) {
				document.location = save.href; 
// window event not working here
			}else{
		        var evt = new MouseEvent('click', {
		            'view': window,
		            'bubbles': true,
		            'cancelable': false
		        });
		        save.dispatchEvent(evt);
		        (window.URL || window.webkitURL).revokeObjectURL(save.href);
			}	
    }

    // for IE < 11
    else if ( !! window.ActiveXObject && document.execCommand)     {
        var _window = window.open(fileURL, '_blank');
        _window.document.close();
        _window.document.execCommand('SaveAs', true, fileName || fileURL)
        _window.close();
    }
}

download_file('https://www.antennahouse.com/XSLsample/pdf/sample-link_1.pdf', 'fileName.pdf'); //call function