readonly fino a onChnage

[var]

<input type="text" name="nome" onblur="f(this.f, this.value);" />

dove f e':

function f(myf, v){
 var e=myf.elements;
 for(var i=0;i<e.length;i++) if(e[i].type=="checkbox") e[i].readOnly=(v=='');

fammi sapere.

ciao