JavaScript function to replace/highlight any content within html

replace_within_tags.js

var replace_within_tags=function(str,find,replace){//replace_within_tags('<a href="javascript:;"> an example <span> another <b>exa</b>mple</span> </a>','exa','EXA');
				str=str+'';
				find=(find+'').toLowerCase();
				replace=replace+'';
				var c='',tag_open=false,out='',temp='';
			for(var i=0;i<str.length;i++){
				c=str.substr(i,1);
				switch(c){
					case '<':
							out+=temp;
							temp='';
						tag_open=true;
						out+=c;
					break;
					case '>':
							out+=temp;
							temp='';
						tag_open=false;
						out+=c;
					break;
					default:
						if(tag_open==false){
							temp+=c;				
							if( find.substr(0,temp.length)==temp.toLowerCase()){
									if(find.length==temp.length){
										out+=replace;
										temp='';
									}
							}else {
								out+=temp;
								temp='';
							}
						}else{
							out+= c;
						}
					break;
				}
					
			}
				return out+temp;
		};
    
    replace_within_tags('<a href="javascript:;"> an example <span> another <b>exa</b>mple</span> </a>','exa','EXA');