js commands that generate and display the drawing:
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imgurl=generateGuid();
postFile('functions/draw2DSpring.php','params='+paramstring+'&imgurl='+imgurl);
document.getElementById('drawingdiv').innerHTML='<img id="drawing" src="tmpimg/'+imgurl+'.png" />';


example params sent:
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params={"springType":0,"wireDiameter":{"metricValue":2.4,"convValue":2.4,"unitType":"1","unitName":"mm"
},"outsideDiameter":{"metricValue":20,"convValue":20,"unitType":"1","unitName":"mm"},"freeLength":{"metricValue"
:40,"convValue":40,"unitType":"1","unitName":"mm"},"solidLength":{"metricValue":19.2,"convValue":19.2
,"unitType":"1","unitName":"mm"},"totalCoils":8,"activeCoils":6,"tipThickness":"50"}&imgurl=CE0931BB
-3E39-82A9-74BF-1595799B7E96