function strstr(){
var str $("#str").val(); //STRING HAYSTACK
var needle $("#needle").val(); //NEEDLE
var n = str.indexOf(needle); //POSITION OF FIRST "NEEDLE" IN THE STRING

if(needle){
if(n>=0){
var s = str.split(needle); //SPLITS STRING BY THE "NEEDLE"
var before = s[0]; //SUBSTR BEFORE THE FIRST "NEEDLE"
var after = ''; //(IMPORTANT) NULL VARIABLE UNTIL INSIDE THE "FOR LOOP"

for(i=n; i<str.length; i++){
after += str[i];
}

$("#strstr").html("Before Needle: <b>"+before+"</b> On after: <b>"+after+"</b>"); //DISPLAYS BOTH PARTS IN HTML
}
{
$("#strstr").html("Needle not found in string.");
}
}
{
$("#strstr").html("");
}
}