Dynamic Select
<script>
function SelReceiverNameChange(){
document.frmSendSms.receiverPhoneNum.value=document.frmSendSms.selReceiverName.value;
}
</script>
<form name="frmSendSms" method="post" action="#">
<input name="receiverPhoneNum" id="receiverPhoneNum" type="text" value="" onkeypress="receiverPhoneNumChange()" onkeydown="receiverPhoneNumChange()" onkeyup="receiverPhoneNumChange()">
<select name="selReceiverName" onChange="SelReceiverNameChange()" >
<OPTION SELECTED VALUE="">- Choose -
<OPTION VALUE="sym">az
<OPTION VALUE="si">ti
<OPTION VALUE="e">toi
</select>