Pause not works in eval Coroutine

Hi, all. Why eval not support wait in Coroutine?
I want run one long time Coroutine script in eval, but eval skip WaitForSeconds() without delay.
Maybe you have other ideas?

var z=0; 
var scr="z=z+1;WaitForSeconds(1);//other code";

function Do () {
    Debug.Log("Do now");
    eval(scr);
    Debug.Log("Do any seconds later"+z);
    eval(scr);
    Debug.Log("Do any seconds later"+z);
    eval(scr);
    Debug.Log("Do any seconds later"+z);	
}

function Start () {
	StartCoroutine("Do");
	Debug.Log("Start complte");	
}

I do not know if what you’re trying to do here will work at all, but I do know that you need to use the ‘yield’ keyword before WaitForSeconds:

var scr="z=z+1;[B]yield[/B] WaitForSeconds(1);//other code";

Not tested or anything and, again, no idea if what you want can be done.

Thanks i’m try add yield, but this not works.