sharepoint - Call Javascript method from code behind c# -

please me solve challenge:( have below code:

label lblvideoassessment = new label();                         lblvideoassessment.text = "<a href='../sitepages/assessment.aspx?cat=" + cat + "' height='300px' width='300px' target='_blank' cssclass='icondisplaycss'><img src='~/_layouts/images/assessment.png' border='none'/></a><br/>" + cat; 

i want replace above code dialogue box instead of opening new page "Ässessment.aspx". have tried this:

lblvideoassessment.text = "<a cssclass='icondisplaycss' width='300px' height='300px' onclick='javascript:opendialog('../sitepages/assessment.aspx?cat='+cat+);return false;'><img border='none' src='~/_layouts/images/assessment.png'></a>"; 

however doesnot work. think issue ''(quotation have placed ) or need use page.clientscript.registerstartupscript

if yes...how , place it?

please have been struggling fort night.

i had got suggestion use literal control.i have tried , not work.

var strscript = "<script language=\"javascript\" type=\"text/javascript\">"; strscript += "alert(\"hello\")"; strscript += "</script>"; page.clientscript.registerclientscriptblock(gettype(), "onload", strscript, false); 

good luck!

edit:

var script = "<script language=\"javascript\" type=\"text/javascript\">$('#tag').click(function () {})</script>"; page.clientscript.registerclientscriptblock(gettype(), "ready", script , false); 

finally:

var script = "<script language=\"javascript\" type=\"text/javascript\">$(\".icondisplaycss\").click(function () {opendialog('../sitepages/assessment.aspx?cat='" + cat + "); });</script>" page.clientscript.registerclientscriptblock(gettype(), "ready", script , false);