$(document).ready(function(){
int1 = setInterval( function(){lightning_one()}, 4000 );
});
$(document).ready(function(){
int1 = setInterval(lightning_one, 4000 );
});
$(document).ready(function(){
int1 = setInterval( function(){
lightning_one(param1,param2);
someFunction_1();
someFunction_2();
}, 4000 );
});