using setTimeout when using prototype

I have an object, and I define the following:
var processForm=new Object();

processForm=function(inservleturl) {
this.inservleturl = inservleturl;
this.submitForm();
}

processForm.prototype.submitForm2=function() {
}

processForm.prototype.submitForm=function() {
setTimeout("submitStep2()", 20);
}


How can the submitForm function's setTimeout call submitStep2?

Thank you.

.