alert("第一行/n第二行");

String strTemp="歷史答題報告：//n"+"您答對了"+RdData.getCcnt()+"道題//n"+"您有"+RdData.getBcnt()+"道題沒答//n"+"您答錯"+RdData.getWcnt()+"題//n";
out.print("<script> alert('"+strTemp+"');window.location='index.jsp'</script>");

Code Outputs
/' single quote
/" double quote
// backslash
/n new line
/r carriage return
/t tab
/b backspace
/f form feed