// JS:

function searchData()
{
var suchfeld = document.getElementById("suchfeld").value;

var url = "content.jsp?suche=" + suchfeld;

var frame =  document.getElementById("mac");
frame.setAttribute("src", url);
}

// Textbox
<textbox id="suchfeld" width="150"  flex="1" type="autocomplete">

// Button
<button label="Suche" id="searchbutton" oncommand="searchData();" />

// Iframe
<iframe flex="9" id="mac" src="test.jsp" frameborder="0" />