From Chickenfoot Script Repository
/**
* Exact Find - exactfind(str)
* Strips tags from the body of the page, then search for string str.
* If there is a match, returns true. Otherwise, returns false.
*
* @author khamer
* @date November 5, 2008
*/
function strip_tags(str,allowed_tags){var key='',tag='',allowed=false;var matches=allowed_array=[];var allowed_keys={};var replacer=function(search,replace,str){return str.split(search).join(replace);};if(allowed_tags){allowed_array=allowed_tags.match(/([a-zA-Z]+)/gi);}
str+='';matches=str.match(/(<\/?[^>]+>)/gi);for(key in matches){if(isNaN(key)){continue;}
html=matches[key].toString();allowed=false;for(k in allowed_array){allowed_tag=allowed_array[k];i=-1;if(i!=0){i=html.toLowerCase().indexOf('<'+allowed_tag+'>');}
if(i!=0){i=html.toLowerCase().indexOf('<'+allowed_tag+' ');}
if(i!=0){i=html.toLowerCase().indexOf('</'+allowed_tag);}
if(i==0){allowed=true;break;}}
if(!allowed){str=replacer(html,"",str);}}
return str;}
function exactfind(str){content=strip_tags(document.body.innerHTML)
return(content.indexOf(str)>-1);}