Onclick event for a div to show a popup window

Hi

I want to add onclick function for a div in tile grid so that when i click on that div a new pop window will appear . When i tried to append onclick function using string bulider the follwing error occures .

*********************** The method append(Object) in the type StringBuilder is not applicable for the arguments (void)****************

Is their any other way to add onclick function for a div.How can I over come this issue . Iam including the code which appends the various div elements in a tile grid cell.



final StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append("<div class='articleTile'>");
{
stringBuilder.append("<div class='context'>");
{
stringBuilder.append("<div class='icon-product'>").append("<div class='icon ").append(getProductTypeClass(record)).append("'></div>").append("</div>");
stringBuilder.append("<div class='divider'>|</div>");

if (record.getAttributeAsInt("letid") == 0) {
stringBuilder.append("<div class='icon-star'>");
} else {
stringBuilder.append("<div class='icon-star icon-star-gold'>");
}

stringBuilder.append("<i class='fa fa-star'></i></div>");
stringBuilder.append("<div class='Ceoname'>").append(defaultIfNullAttribute("source", record)).append("</div>");

final String author = record.getAttribute("author");

if (author != null && author.trim().length() > 0) {
stringBuilder.append("<div class='divider'>|</div>");
stringBuilder.append("<div class='ownerName'>").append(record.getAttribute("author")).append("</div>");
}

stringBuilder.append("<div class='divider'>|</div>");
stringBuilder.append("<div class='crtdDate'>").append(DateUtil.format(record.getAttributeAsDate("harvesttime"), "d-MMM-YYYY")).append("</div>");

stringBuilder.append("<div class='divider'>|</div>");
stringBuilder.append("<div class=''>").append("<i class='sample-copy' title='Syndicates'></i> ").append(record.getAttributeAsInt("Count"));
stringBuilder.append("</div>");

stringBuilder.append("<div class='abst_ind_article' align=right> <a onclick=").append(modelwindow.show()).append("></a>+ Add to name list</div>");
}
stringBuilder.append("</div>");

stringBuilder.append("<div class='headline'><a target='_blank' href='").append(record.getAttribute("eurl")).append("'>").append(defaultIfNullAttribute("headline", record)).append("</a></div>");
stringBuilder.append("<div class='content'>").append(getContent(record)).append("</div>");
}
stringBuilder.append("</div>");

return stringBuilder.toString();
}



*****I have to add onclick for div class='abst_ind_article'.


Thanks