Result of expression 'this.getURL'[undefined] is not a function
<p>When i call a method directly without a setInterval the function works correctly</p>

<pre><code>slider.prototype.onTouchEnd = function(e){
    clearInterval(this.inter);
    this.getURL(this.url + '/' + this.eid.id  + '/' + this.currX);
    e.preventDefault();
}
</code></pre>

<p>putting the same function in a setInterval give me following error:
Result of expression 'this.getURL'[undefined] is not a function</p>

<pre><code>slider.prototype.onTouchStart = function(e){
    e.preventDefault();
    this.inter = setInterval("this.getURL('www.google.com')",100);
}
</code></pre>

<p>the code of getURL is:</p>

<pre><code>slider.prototype.getURL = function(url){
    console.log(url);
    verzoek=new XMLHttpRequest();
    verzoek.onreadystatechange=function(){
        if(verzoek.readyState==4) {
            if(verzoek.status==200) {
                var data=verzoek.responseText;
            }
        }
    }
    verzoek.open("GET", url, true);
    verzoek.send(null);
}
</code></pre>

<p>the this.inter is created in the constructor</p>

<pre><code>var slider = function(eid){
    ...
    this.inter = null;  
}
</code></pre>

<p>I tried so many things but it keeps failing.</p>

<p>Thx in advance</p>
