Answers for "javascript change text in iframe"

change element in iframe

// so you got an iframe (id="myiframe"). In that page you have an element id="theprice" and you want to change its value
// from the parent page do this in your javascript:
var iframevar = document.getElementById('myiframe');
var elmnt = iframevar.contentWindow.document.getElementById("theprice");
elmnt.innerHTML = theNewPrice;

detect iframe content change javascript

$('#iframe').on('load', function() {
    alert('frame has (re)loaded ');
});