Alert Box size

Alert Box size

Hi,

I have set up a alert on user input but it seems the alert size is really too big. How do I can size it to smaller ? 
Below is the script that I am using 

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if (input.UNM_MVPD_01  !=  null  )
{
    input.UNM_alertNote = ((((((((((("The " + "<b>" + "<i>" + MVPD[ID == input.UNM_MVPD_01].mvpd_MVPDName + "</i>" + "</b>" + " in " + "<b>" + "<i>" + Market[ID == dat.Add_Market].Market_Name + "</i>" + "</b>" + " TV Market Sold to " + "<b>" + "<i>" + MVPD[ID == alrtFrm_count1.mvpdaf_BoughtByMVPD].mvpd_MVPDName) + "</i>") + "</b>") + ". ") + "'") + "<b>") + "<i>") + MVPD[ID == alrtFrm_count1.mvpdaf_BoughtByMVPD].mvpd_MVPDName) + "</i>") + "</b>") + "'") + " is Selected";

    alert( input.UNM_alertNote + "<br>"+"<div style='line-height: 10pt;'>" + "Related Description:- "  + alrtFrm_count1.mvpdaf_RelatedNote + "</div>");
   
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Screenshot of alert