1. Your using the same open and closing " " in one string line.
2. You declaring a function. I suggest you don't and just use the line by itesle. unless your function becomes really largly functional
No
"myFunction()
{
document.elementById("myid").innerHTML = "TESTE";
}"
Try
" document.elementById('myid').innerHTML = 'test'; "
notice the change in the qoute type for internal qoutes.