var array = [11, 20, 8, 6, 17];
var el = 6; //Element to be searched
var flag = 0; // Initially 0 - Not found
for(var i=0; i<array.length; i++) {
if(el === array[i]) {
flag = 1;
}
}
//Check if flag value changed.
if(flag == 1) {
console.log('Element Found');
} else {
console.log('Element Not Found');
}