Its usually a bad idea to try and combine server code and client strings inside the quotes of a property (ie onclick="something@(something())" )
Its better to just return the entire lot in a server side function
Here's how I would rework your code:
<a href="#" style="color:#0564c1;"
onclick="@Html.Raw(
String.Format(
"PopUpStart('POST','','',200,100,'{0}','{1}','ReloadPage',true);return false;"
, Url.Action("index",address,new{id = baseObject.Id, type = dataTypeInt})
, Url.Action("cancel",address,new{id = baseObject.Id, type = dataTypeInt})
)
)"/>
Edit
</a>