JQuery UI Autocomplete set default value using ID (key or value) instead of Label

JQuery UI Autocomplete set default value using ID (key or value) instead of Label

dear all,
i've created a JQuery UI Autocomplete in which the source is an array of label-value pairs.
i need to set the default selected item. i found a way to do that using the desired label,
but how can i do that if i have the VALUE instead of the LABEL ?
 
code for setting default value using label string : 

  1. $("myAutoCom").autocomplete("search", "someLabel");
var menu = $("myAutoCom").autocomplete("widget");
$(menu[0].children[0]).click();

 
i have the value,not the label. how can i set selected item depending on value?
thanks in advance