Best answer I found was to create a global variable. Probably like this less than using AddHandler type coding but at least it keeps my javascript WITH my javascript.
<script>
var gvCompanySelectorClientID = = '<%= gvCompanySelector.ClientID %>';
function showCompanySelector(divName,gridName) {
var elem = document.getElementById(divName);
var gridElem = document.getElementById(gridName);
if (elem.style.visibility === 'visible') {
elem.style.visibility = 'hidden';
elem.style.height = '0px';
gridElem.style.height = '0px';
}
else {
elem.style.visibility = 'visible';
elem.style.height = '200px';
gridElem.style.height = null;
}
}
</script>
<asp:HyperLink ID="aShowList" runat="server" onclick="javacript:showCompanySelector('divCompanySelector','<%= gvCompanySelectorClientID %>');" CssClass="button">Select</asp:HyperLink>
Would love any other recommendations.