/* send first parameter as the link object itself - use ( this ) in function call,
		second parameter as the id of the element you wish to show/hide */
		function doviewiframe(linkElem,elemId) {
		//toggle the link elements innerHTML
		linkElem.innerHTML = linkElem.innerHTML === "Hide" ? "Show" : "Hide";
		//get the current display property of the element to toggle
		var isitshown = document.getElementById(elemId).style.display;
		//toggle the display property of the element
		// note the style tag giving the elemtent a display property initially
		document.getElementById(elemId).style.display = isitshown === "block" ? "none" : "block";
		} 
	    
	/* use like this 
	 .iframePopup { 
		display:none; 
		}
	 .hideiframe { 
		line-height:16px;
		font-size:14px;
		font-weight:bold;
		font-family:sans-serif;
		color:brown;
		text-decoration:none; 
		} 
	
	<div>
		<a href="#" class="hideiframe" onclick="doviewiframe(this,'iframe'); return false;"> Click to Show </a>
		<br/><br/>
		<div class="iframePopup">
			<iframe frameborder="1" height="200" name="frame1" scrolling="yes" src="http://www.example.com" width="550"></iframe>
		</div>
	</div>
	
	
	
	or........................ 
	<?php
	  
		function loadIframeLink($link, $index){
			$iframe = '
				<div>
				<span class="iFrameLinkTitle">' . $link[$index][ 'text' ] . '</span>
				<a href="#" class="hideiframe" onclick="doviewiframe(this,\'iframe'.$index.'\'); return false;"> Show </a>
				<br/><br/>
				<div class="iframePopup" id="iframe'.$index.'">
					<iframe frameborder="1" height="200" name="frame'.$index.'" scrolling="yes" src="'.$link[$index]['src'].'" width="550"></iframe>
				</div>
				</div>';
			echo $iframe; 
		}
			 
		$link[] = array(
			'text'=>'Nonmenclature',
			'src'=>'http://www.zoonomen.net/avtax/frame.html');
		$link[] = array(
			'text'=>'Data Logging',
			'src'=>'http://www.pwrc.usgs.gov/bba/BBA_info_mgmt.htm');
		$link[] = array(
			'text'=>'Reorganizing Species List due DNA',
			'src'=>'http://www.calacademy.org/science_now/academy_research');
		loadIframeLink($links, '0');
		loadIframeLink($links, '1');
		loadIframeLink($links, '2');
		?>	  
	*/