Page stuck at processing when I call javascript method from fnDrawCallback().

I tried to highlight text in my <tbody> and so I was calling a js that do this from fnDrawCallback(). In this js, the innerHtml is getting replaced with new style. Due to this my page stuck at Processing. Any solutions?

function doHighlight(bodyText, searchTerm, highlightStartTag, highlightEndTag) 
{
// the highlightStartTag and highlightEndTag parameters are optional
if ((!highlightStartTag) || (!highlightEndTag)) 
{
highlightStartTag = "<font style='color:blue; background-color:yellow;'>";
highlightEndTag = "</font>";
}

var newText = "";
var i = -1;
var lcSearchTerm = searchTerm.toLowerCase();
var lcBodyText = bodyText.toLowerCase();

while (bodyText.length > 0) {
i = lcBodyText.indexOf(lcSearchTerm, i+1);
if (i < 0) {
  newText += bodyText;
  bodyText = "";
} else {
  // skip anything inside an HTML tag
  if (bodyText.lastIndexOf(">", i) >= bodyText.lastIndexOf("<", i)) {
    // skip anything inside a <script> block
    if (lcBodyText.lastIndexOf("/script>", i) >= lcBodyText.lastIndexOf("<script", i)) {
    	if (lcBodyText.lastIndexOf("/thead>", i) >= lcBodyText.lastIndexOf("<thead", i)) {
	      newText += bodyText.substring(0, i) + highlightStartTag + bodyText.substr(i, searchTerm.length) + highlightEndTag;
	      bodyText = bodyText.substr(i + searchTerm.length);
	      lcBodyText = bodyText.toLowerCase();
	      i = -1;
	    }
    }
  }
}
}

return newText;
}