Calculating elapsed time from two variables

[bklernr]

Hello,

I'm working on a form in Acrobat Pro 9 (not LiveCycle). I need to have an operator enter a beginning time (firsttime) & an end time (secondtime) & when s/he pushes a button (btncalcmix.0), the form calculates the total elapsed time. It must take into consideration that a test could begin at 4 pm & end at 8 am the next day. This is what I've put together so far.....but it doesn't work. I get this message: syntax error 10: at line 11.

// if button pushed, calculate mix time
 
var f=this.getField("btncalcmix.0");
this.getField ("ttlmix").value = this.getField("dateform.secondtime").value - this.getField("dateform.firsttime").value;
 
if ((this.getField("dateform.secondtime").value)="" || (this.getField("dateform.firsttime").value="")); {
this.getField("ttlmix").value = 0;
}
 
if((this.getField("dateform.secondtime").value) <- this.getField("dateform.firsttime").value)) {
((this.getField ("ttlmix").value)*24)+24; 
} else {
this.getField("ttlmix").value)*24));
}
 
if (f.value!= "true") {
this.getField("ttlmix")=util.printd("HH:MM:ss", new Date());
}
 

Any suggestions? Thank you in advance.

[Dormilich]

too many closing parentheses (1 open, 4 closing)