Not able to break a label in two line in ms crm 2016

Hi guys , 

I need to break a label in two line . For this I added a javascript function and calling a formLoad event.

some times  it shows for a sec and vanishes. I m using ms crm 2016 on line.

**********************************************----------------------------------------------------------*************************************

function funsetLabel()
{
message = "first message" + '<br/>';
message = message + "second message";
var k = window.parent.document.getElementById("accen_field2_cl")
if(k == null)
{
alert("kk");
}
else
{
window.parent.document.getElementById("accen_field2_cl").innerText = message;

k.innerText =message;   
k.isContentEditable = true;
alert("tttttttt");  // working

window.parent.document.getElementById("accen_field2_cl").style.background="red"; // this is working
}

********************************************-----------------------------------------------------------**********************************