Very simple, fragile, multi-line text parsing in javascript

multiline_text_parser.js

// Let's parse the lines in from our textarea

var textarea = $("#mytextarea").val();

// Different browsers represent end of lines differently, so make all end of lines \n */
lines = textarea.replace(/\r\n/g, "\n").split("\n");

// Set up state variables to help track parsing across multiple lines
var line_parser_state = "listitem";
var block_content = "";

lines.forEach(function(entry) {
    if (entry.trim()!="") { 

      // Line starts with ``` indicating start quote/code block if current state is "listitem"
      if (entry.match(/```/) && "listitem" == line_parser_state ) {
        // change states
        line_parser_state = "codeblock"
        // start code block
        block_content = "<pre>";
        return;
      }

      // Line starts with ``` indicating end quote/code block if current state is "codeblock"
      if (entry.match(/```/) && "codeblock" == line_parser_state) {
        // append block_content and close code block
        $("#timers").append(block_content + "</pre>");
        // reset line_parser_state
        line_parser_state = "listitem";
        return;
      }

      // Line does not start with ``` indicating line of codeblock if current state is "codeblock"
      if (!entry.match(/```/) && "codeblock" == line_parser_state ) {
        // line that is part of code block
        line_parser_state = "codeblock"
        // append line to block_content
        block_content = block_content + entry + "\n";
        return;
      }

      // Line starts with # - Create section heading and heading timer
      if (entry.match(/#/)) {
        line_parser_state = "sectionheading";
        // Remove `#`'s 
        entry = entry.replace(/#*/g,'');
        $("#timers").append("<h4 style='border-bottom: 1px solid #ccc;'>"+entry+"</h4>\n");
        // Put heading as a timer in parantheses
        entry = "("+entry+")";
        line_parser_state = "listitem";
        return;
      }

      // Line starts with keyword "Note:" or "comment:" - indicating a note or comment (case insentive)
      if (entry.match(/note:|comment:/ig)) {
        line_parser_state = "indentedline";
        $("#timers").append("<div style='margin-left:20px;'><i>"+entry.trim()+"</i></div>\n");
        entry = "("+entry+")";
        line_parser_state = "listitem";
        return;
      }

      // Append a line using a template
      $("#timers").append($("#myformattemplate").val().replace(/{{entry}}/g, entry)); 
    }
});