Paul's JavaScript Examples | ||
Convertor script to convert pounds to kilograms and kilograms to pounds. 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=computeWeightForm(this.form)> <INPUT TYPE="button" VALUE="Clear" onClick=clearWeightForm(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 computeWeightForm(weightform) { // if both forms empty - error if ( (weightform.kilogram.value == null || weightform.kilogram.value.length == 0) && (weightform.pound.value == null || weightform.pound.value.length == 0) ) { alert("Both fields empty."); return; } // if both forms filled error if ( (weightform.kilogram.value != null && weightform.kilogram.value.length > 0) && (weightform.pound.value != null && weightform.pound.value.length > 0) ) { alert("Error: both fields have data."); return; } // calculate kilograms if ( (weightform.kilogram.value == null || weightform.kilogram.value.length == 0) && (weightform.pound.value != null && weightform.pound.value.length > 0) ) { if (checkNumber(weightform.pound,"Pounds")) { weightform.kilogram.value = (weightform.pound.value * 0.455); } } // calculate pounds if ( (weightform.kilogram.value != null && weightform.kilogram.value.length > 0) && (weightform.pound.value == null || weightform.pound.value.length == 0) ) { if (checkNumber(weightform.kilogram,"Kilograms")) { weightform.pound.value = (weightform.kilogram.value / 0.455); } } } // used for weight conversion function clearWeightForm(weightform) { weightform.kilogram.value=""; weightform.pound.value=""; } // --> </SCRIPT>