The way I would like to do this is to make text input as a filter for the drop-down list. The user can either select something from the list or enter several characters to filter or continue entering and create a unique line. Put a size property of, say, 6 in SELECT so that it appears as a selectable list instead of a button.
<div> <input id="mySelectInput type="text" onchange="filterSelect()"/><br/> <select id="mySelect" size="6"> </select> </div>
Then just write the filterSelect () function
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