Paul's JavaScript Examples | ||
Convertor script to convert kilometers to miles and miles to kilometers. Just fill in one value and click on the Convert button. use the Clear button to clear the values. Note, negative values are not supported.
Example
Usage
<INPUT TYPE="button" VALUE="Convert" onClick=computeDistForm(this.form)> <INPUT TYPE="button" VALUE="Clear" onClick=clearDistForm(this.form)>
Source
<SCRIPT LANGUAGE="javascript"> <!-- function checkNumber(numStr, fieldName) { msg = fieldName + " field has invalid data: " + numStr.value; str = numStr.value; for (var i=0; i < str.length; i++) { var ch = str.substring(i,i+1); if ( (ch < "0" || ch > "9") && ch != '.' ) { alert(msg); return false; } } return true; } function computeDistForm(distform) { // if both forms empty - error if ( (distform.km.value == null || distform.km.value.length == 0) && (distform.mile.value == null || distform.mile.value.length == 0) ) { alert("Both fields empty."); return; } // if both forms filled error if ( (distform.km.value != null && distform.km.value.length > 0) && (distform.mile.value != null && distform.mile.value.length > 0) ) { alert("Error: both fields have data."); return; } // calculate kilometers if ( (distform.km.value == null || distform.km.value.length == 0) && (distform.mile.value != null && distform.mile.value.length > 0) ) { if (checkNumber(distform.mile,"Miles")) { distform.km.value = (distform.mile.value * 1.60934); } } // calculate miles if ( (distform.km.value != null && distform.km.value.length > 0) && (distform.mile.value == null || distform.mile.value.length == 0) ) { if (checkNumber(distform.km,"Kilometers")) { distform.mile.value = (distform.km.value / 1.60934); } } } // used for distance conversion function clearDistForm(distform) { distform.mile.value=""; distform.km.value=""; } // --> </SCRIPT>