使用HTML按钮调用带参数的JavaScript函数

Question

I am trying to call a JavaScript function with parameters via HTML button.

HTML:

<input id="clickMe" type="button" value="clickme" onclick="callFunc("<?php $x='Hello World'; echo $x; ?>")" />

JavaScript:

/*

* Convert string to a base-64 string

*/

function str2b64(input) {

  try { b64pad } catch(e) { b64pad=''; }

    var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    var output = "";
    var len = input.length;
    for(var i = 0; i < len; i += 3) {
        var triplet = (input.charCodeAt(i) << 16)
                | (i + 1 < len ? input.charCodeAt(i+1) << 8 : 0)
                | (i + 2 < len ? input.charCodeAt(i+2)      : 0);
        for(var j = 0; j < 4; j++) {
            if(i * 8 + j * 6 > input.length * 8) output += b64pad;
            else output += tab.charAt((triplet >>> 6*(3-j)) & 0x3F);
        }
    }
  alert(output);

}

What I get at run time or on click is absolutely NOTHING! As soon as I remove the variable I am passing it works as intended.

Not sure why I am having issues but regardless any help is greatly appreciated!

Thanks!