PDF Range and Checkboxes

I am so painfully new at this - if this is the wrong area to post, let me know. I am working in a PDF (when mouse up, run a javascript) and would like the following:
If textfield1 contains 3-37 then checkbox1 is on/checked
if textfield1 contains 38-46 then checkbox2 is checked
if textfield1 contains 47-55 then checkbox3 is checked
if textfield1 contains >56 then checkbox4 is checked

It seems simple enough, but my brain can't get it to work.

 

You need to do a if-else condition. So google "pdf javascript if else with numbers" and then google "pdf javascript checkbox". It doesn't seem like you have tried that yet. Do you have actual code to debug or no idea where to start? A good start would be searching those phrases

 

Thanks for the tips, but I've obiviously in over my head, I'm not getting an error but I am also not getting a check:

if (this.getField("CheckBox1").value!="Off")
{this.getField("TOTAL1").value = 37
this.getField("CheckBox1").checkThisBox(0,event.target.value= "On");
}
else{
event.value = 0;
this.getfield("CheckBox1").checkThisBox(0,event.target.value= "Off");
}