javascript - Problems with option selection in Chrome and Opera -

i've problems thise code, it's working fine in firefox , internet explorer doesn't work opera , chrome browsers...

<script> function planetselect() { optionen=document.getelementbyid('pstart').options; for(i=0;i<optionen.length;i++) { if(optionen[i].value==67080) {   optionen[i].setattribute('selected','selected');   } } optionen=document.getelementbyid('pdest').options; for(i=0;i<optionen.length;i++) { if(optionen[i].value==67080) {   optionen[i].setattribute('selected','selected');   } } }</script> 

change

optionen[i].setattribute('selected','selected'); 

to

optionen[i].selected = true; 

more generally, avoid use of setattribute change dom properties. works, doesn't.

from the mdn :

using setattribute() modify attributes, notably value in xul, works inconsistently, attribute specifies default value. access or modify current values, should use properties. example, use elt.value instead of elt.setattribute('value', val).